What is "block"

Block \Block\ (bl[o^]k), n. [OE. blok; cf. F. bloc (fr. OHG.), D. & Dan. blok, Sw. & G. block, OHG. bloch. There is also an OHG. bloch, biloh; bi by + the same root as that of E. lock. Cf. Block, v. t., Blockade, and see Lock.]

1. A piece of wood more or less bulky; a solid mass of wood, stone, etc., usually with one or more plane, or approximately plane, faces; as, a block on which a butcher chops his meat; a block by which to mount a horse; children's playing blocks, etc.

   Now all our neighbors' chimneys smoke, And Christmas blocks are burning.
   --Wither.

   All her labor was but as a block Left in the quarry.
   --Tennyson.

2. The solid piece of wood on which condemned persons lay their necks when they are beheaded.

   Noble heads which have been brought to the block.
   --E. Everett.

3. The wooden mold on which hats, bonnets, etc., are shaped. Hence: The pattern or shape of a hat.

   He wears his faith but as the fashion of his hat; it ever changes with the next block.
   --Shak.

4. A large or long building divided into separate houses or shops, or a number of houses or shops built in contact with each other so as to form one building; a row of houses or shops.

5. A square, or portion of a city inclosed by streets, whether occupied by buildings or not.

   The new city was laid out in rectangular blocks, each block containing thirty building lots. Such an average block, comprising 282 houses and covering nine acres of ground, exists in Oxford Street.
   --Lond. Quart. Rev.

6. A grooved pulley or sheave incased in a frame or shell which is provided with a hook, eye, or strap, by which it may be attached to an object. It is used to change the direction of motion, as in raising a heavy object that can not be conveniently reached, and also, when two or more such sheaves are compounded, to change the rate of motion, or to exert increased force; -- used especially in the rigging of ships, and in tackles.

7. (Falconry) The perch on which a bird of prey is kept.

8. Any obstruction, or cause of obstruction; a stop; a hindrance; an obstacle; -- also called blockage; as, a block in the way; a block in an artery; a block in a nerve; a block in a biochemical pathway.

9. A piece of box or other wood for engravers' work.

10. (Print.) A piece of hard wood (as mahogany or cherry) on which a stereotype or electrotype plate is mounted to make it type high.

11. A blockhead; a stupid fellow; a dolt. [Obs.]

    What a block art thou !
    --Shak.

12. A section of a railroad where the block system is used. See Block system, below.

13. In Australia, one of the large lots into which public land, when opened to settlers, is divided by the government surveyors.

14. (Cricket)

    1. The position of a player or bat when guarding the wicket.

    2. A block hole.

    3. The popping crease. [R.]

15. a number of individual items sold as a unit; as, a block of airline ticketes; a block of hotel rooms; a block of stock.

16. the length of one side of a city block[5], traversed along any side; as, to walk three blocks ahead and turn left at the corner.

17. a halt in a mental process, especially one due to stress, memory lapse, confusion, etc.; as, a writer's block; to have a block in remembering a name.

18. (computers) a quantity of binary-encoded information transferred, or stored, as a unit to, from, or on a data storage device; as, to divide a disk into 512-byte blocks.

19. (computers) a number of locations in a random-access memory allocated to storage of specific data; as, to allocate a block of 1024 bytes for the stack. A block of shares (Stock Exchange), a large number of shares in a stock company, sold in a lump. --Bartlett. Block printing.

    1. A mode of printing (common in China and Japan) from engraved boards by means of a sheet of paper laid on the linked surface and rubbed with a brush.
       --S. W. Williams.

    2. A method of printing cotton cloth and paper hangings with colors, by pressing them upon an engraved surface coated with coloring matter.

       Block system on railways, a system by which the track is divided into sections of three or four miles, and trains are so run by the guidance of electric signals that no train enters a section or block before the preceding train has left it.

       Back blocks, Australian pastoral country which is remote from the seacoast or from a river.

Block \Block\ (bl[o^]k), v. t. [imp. & p. p. Blocked (bl[o^]kt); p. pr. & vb. n. Blocking.] [Cf. F. bloquer, fr. bloc block. See Block, n.]

1. To obstruct so as to prevent passage or progress; to prevent passage from, through, or into, by obstructing the way; -- used both of persons and things; -- often followed by up; as, to block up a road or harbor; to block an entrance.

   With moles . . . would block the port.
   --Rowe.

   A city . . . besieged and blocked about.
   --Milton.

2. To secure or support by means of blocks; to secure, as two boards at their angles of intersection, by pieces of wood glued to each.

3. To shape on, or stamp with, a block; as, to block a hat.

4. to cause (any activity) to halt by creating an obstruction; as, to block a nerve impulse; to block a biochemical reaction with a drug.

   To block out, to begin to reduce to shape; to mark out roughly; to lay out; to outline; as, to block out a plan.

"obstruct," 1590s, from French bloquer "to block, stop up," from Old French bloc (see block (n.)). Meaning "to make smooth or to give shape on a block" is from 1620s. Stage and theater sense is from 1961. Sense in cricket is from 1772; in U.S. football from 1889. Related: Blocked; blocking.

"solid piece," c.1300, from Old French bloc "log, block" of wood (13c.), via Middle Dutch bloc "trunk of a tree" or Old High German bloh, from a common Germanic source, from PIE *bhlugo-, from *bhelg- "a thick plank, beam" (see balk).\n

\nMeaning "mould for a hat" is from 1570s. Slang sense of "head" is from 1630s. Extended sense of "obstruction" is first recorded 1640s. In cricket from 1825; in U.S. football from 1912. The meaning in city block is 1796, from the notion of a "compact mass" of buildings; slang meaning "fashionable promenade" is 1869.\n\nBLOCK. A term applied in America to a square mass of houses included between four streets. It is a very useful one.

[Bartlett]

n. 1 A substantial, often approximately cuboid, piece of any substance. 2 A group of urban lots of property, several acres in extent, not crossed by public streets. 3 A residential building consisting of flats. vb. 1 (context transitive English) To fill (something) so that it is not possible to pass. 2 (context transitive English) To prevent (something or someone) from passing. 3 (context transitive English) To prevent (something from happening or someone from doing something). 4 (context transitive sports English) To impede an opponent. 5 (context transitive theater English) To specify the positions and movements of the actors. 6 (context transitive cricket English) To hit with a block. 7 (context intransitive cricket English) To play a block shot. 8 (context transitive English) To disable communication via telephone, instant messaging, etc., with an undesirable someone. 9 (context computing intransitive English) To wait. 10 (context transitive English) To stretch or mould (a knitted item, a hat, etc.) into the desired shape.

1. v. render unsuitable for passage; "block the way"; "barricade the streets"; "stop the busy road" [syn: barricade, blockade, stop, block off, block up, bar]

2. hinder or prevent the progress or accomplishment of; "His brother blocked him at every turn" [syn: obstruct, blockade, hinder, stymie, stymy, embarrass]

3. stop from happening or developing; "Block his election"; "Halt the process" [syn: stop, halt, kibosh]

4. interfere with or prevent the reception of signals; "Jam the Voice of America"; "block the signals emitted by this station" [syn: jam]

5. run on a block system; "block trains"

6. interrupt the normal function of by means of anesthesia; "block a nerve"; "block a muscle"

7. shut out from view or get in the way so as to hide from sight; "The thick curtain blocked the action on the stage"; "The trees obstruct my view of the mountains" [syn: obstruct]

8. stamp or emboss a title or design on a book with a block; "block the book cover"

9. obstruct; "My nose is all stuffed"; "Her arteries are blocked" [syn: stuff, lug, choke up] [ant: unstuff]

10. block passage through; "obstruct the path" [syn: obstruct, obturate, impede, occlude, jam, close up] [ant: free]

11. support, secure, or raise with a block; "block a plate for printing"; "block the wheels of a car"

12. impede the movement of (an opponent or a ball); "block an attack" [syn: parry, deflect]

13. be unable to remember; "I'm drawing a blank"; "You are blocking the name of your first wife!" [syn: forget, blank out, draw a blank] [ant: remember]

14. shape by using a block; "Block a hat"; "block a garment"

15. shape into a block or blocks; "block the graphs so one can see the results clearly"

16. prohibit the conversion or use of (assets); "Blocked funds"; "Freeze the assets of this hostile government" [syn: freeze, immobilize, immobilise] [ant: unblock, unblock]

1. n. a solid piece of something (usually having flat rectangular sides); "the pyramids were built with large stone blocks"

2. a rectangular area in a city surrounded by streets and usually containing several buildings; "he lives in the next block" [syn: city block]

3. a three-dimensional shape with six square or rectangular sides [syn: cube]

4. a number or quantity of related things dealt with as a unit; "he reserved a large block of seats"; "he held a large block of the company's stock"

5. housing in a large building that is divided into separate units; "there is a block of classrooms in the west wing"

6. (computer science) a sector or group of sectors that function as the smallest data unit permitted; "since blocks are often defined as a single sector, the terms `block' and `sector' are sometimes used interchangeably"

7. an inability to remember or think of something you normally can do; often caused by emotional tension; "I knew his name perfectly well but I had a temporary block" [syn: mental block]

8. a simple machine consisting of a wheel with a groove in which a rope can run to change the direction or point of application of a force applied to the rope [syn: pulley, pulley-block]

9. a metal casting containing the cylinders and cooling ducts of an engine; "the engine had to be replaced because the block was cracked" [syn: engine block, cylinder block]

10. an obstruction in a pipe or tube; "we had to call a plumber to clear out the blockage in the drainpipe" [syn: blockage, closure, occlusion, stop, stoppage]

11. a platform from which an auctioneer sells; "they put their paintings on the block" [syn: auction block]

12. (American football) the act of obstructing someone's path with your body; "he threw a rolling block into the line backer" [syn: blocking, interference]

Block may refer to:

A block is an administrative division of some South Asian countries.

In computing (specifically data transmission and data storage), a block, sometimes called a physical record, is a sequence of bytes or bits, usually containing some whole number of records, having a maximum length, a block size. Data thus structured are said to be blocked. The process of putting data into blocks is called blocking, while deblocking is the process of extracting data from blocks. Blocked data is normally stored in a data buffer and read or written a whole block at a time. Blocking reduces the overhead and speeds up the handling of the data-stream. For some devices such as magnetic tape and CKD disk devices blocking reduces the amount of external storage required for the data. Blocking is almost universally employed when storing data to 9-track magnetic tape, to NAND flash memory, and to rotating media such as floppy disks, hard disks, and optical discs.

Most file systems are based on a block device, which is a level of abstraction for the hardware responsible for storing and retrieving specified blocks of data, though the block size in file systems may be a multiple of the physical block size. This leads to space inefficiency due to internal fragmentation, since file lengths are often not integer multiples of block size, and thus the last block of a file may remain partially empty. This will create slack space, which averages half a block per file. Some newer file systems attempt to solve this through techniques called block suballocation and tail merging.

Block storage is normally abstracted by a file system or database management system (DBMS) for use by applications and end users. The physical or logical volumes accessed via block I/O may be devices internal to a server, directly attached via SCSI or Fibre Channel, or distant devices accessed via a storage area network (SAN) using a protocol such as iSCSI, or AoE. DBMSes often use their own block I/O for improved performance and recoverability as compared to layering the DBMS on top of a file system.

In computer programming, a block or code block is a section of code which is grouped together. Blocks consist of one or more declarations and statements. A programming language that permits the creation of blocks, including blocks nested within other blocks, is called a block-structured programming language. Blocks are fundamental to structured programming, where control structures are formed from blocks.

The function of blocks in programming is to enable groups of statements to be treated as if they were one statement, and to narrow the lexical scope of variables, procedures and functions declared in a block so that they do not conflict with variables having the same name used elsewhere in a program for different purposes. In a block-structured programming language, the names of variables and other objects such as procedures which are declared in outer blocks are visible inside other inner blocks, unless they are shadowed by an object of the same name.

In sailing, a block is a single or multiple pulley. One or a number of sheaves are enclosed in an assembly between cheeks or chocks. In use, a block is fixed to the end of a line, to a spar, or to a surface. A line (rope) is reeved through the sheaves, and maybe through one or more matching blocks at some far end, to make up a tackle.

The purchase of a tackle refers to its mechanical advantage. In general the more sheaves in the blocks that make up a tackle, the higher its mechanical advantage. The matter is slightly complicated by the fact that every tackle has a working end where the final run of rope leaves the last sheave. More mechanical advantage can be obtained if this end is attached to the moving load rather than the fixed end of the tackle.

There are various types of blocks that are used in sailing. Some blocks are used to increase mechanical advantage and others are used simply to change the direction of a line. A ratchet block turns freely when a line is pulled in one direction but does not turn the other direction, although the line may slip past the sheave. This kind of block makes a loaded line easier to hold by hand, and is sometimes used on smaller boats for lines like main and jib sheets that are frequently adjusted.

blocks2.JPG|Various types of blocks of both wood and metal found on the 16th century ship Mary Rose on block.jpg|A bird perched near a wooden block 57C block.jpg|A modern single block made of stainless steel and reinforced plastic. The ball bearing is made of Delrin ( polyoxymethylene)

In basketball, a block or blocked shot occurs when a defensive player legally deflects a field goal attempt from an offensive player. The defender is not allowed to make contact with the offensive player's hand (unless it is in contact with the ball) or a foul is called. In order to be legal, the block must occur while the shot is traveling upward or at its apex. A deflected field goal that is made does not count as a blocked shot and simply counts as a successful field goal attempt for shooter plus the points awarded to the shooting team. Every successful blocked shot is counted as a missed field goal attempt for the shooter. Also, on a shooting foul, a blocked shot cannot be awarded or counted, even if the player who deflected the field goal attempt is different from the player who committed the foul. If the ball is heading downward when the defender hits it, it is ruled as goaltending and counts as a made basket. Goaltending is also called if the block is made after the ball bounces on the backboard ( NFHS excepted; the NCAA also used this rule until the 2009–10 season).

Nicknames for blocked shots include "rejections," "stuffs," "bushed", "fudged", or notably "double-fudged" (two-handed blocks), "facials," "swats," "denials," and "packs." Blocked shots were first officially recorded in the NBA during the 1973–74 season.

Largely due to their height and position near the basket, centers and power forwards tend to record the most blocks, but shorter players with good jumping ability can also be blockers, an example being Dwyane Wade, the shortest player, at 6'4", to record 100 blocked shots in a single season. A player with the ability to block shots can be a positive asset to a team's defense, as they can make it difficult for opposing players to shoot near the basket and by keeping the basketball in play, as opposed to swatting it out of bounds, a blocked shot can lead to a fast break, a skill Bill Russell was notable for. To be a good shot-blocker, a player needs great court sense and timing, and good height or jumping ability. One tactic is that a shot-blocker can intimidate opponents to alter their shots, resulting in a miss.

In telecommunications a block is one of:

• A group of bits or digits that is transmitted as a unit and that may be encoded for error-control purposes.
• A string of records, words, or characters, that for technical or logical purposes are treated as a unit. Blocks (a) are separated by interblock gaps, (b) are delimited by an end-of-block signal, and (c) may contain one or more records. A block is usually subjected to some type of block processing, such as multidimensional parity checking, associated with it.

A block transfer attempt is a coordinated sequence of user and telecommunication system activities undertaken to effect transfer of an individual block from a source user to a destination user.

A block transfer attempt begins when the first bit of the block crosses the functional interface between the source user and the telecommunication system. A block transfer attempt ends either in successful block transfer or in block transfer failure.

Successful block transfer is the transfer of a correct, nonduplicate, user information block between the source user and intended destination user. Successful block transfer occurs when the last bit of the transferred block crosses the functional interface between the telecommunications system and the intended destination user. Successful block transfer can only occur within a defined maximum block transfer time after initiation of a block transfer attempt.

In mathematics and group theory, a block system for the action of a group G on a set X is a partition of X that is G-invariant. In terms of the associated equivalence relation on X, G-invariance means that

for all g in G and all x, y in X. The action of G on X determines a natural action of G on any block system for X.

Each element of the block system is called a block. A block can be characterized as a subset B of X such that for all g in G, either

• gB = B (g fixes B) or
• gB ∩ B = ∅ (g moves B entirely).

If B is a block then gB is a block for any g in G. If G acts transitively on X, then the set {gB | g ∈ G} is a block system on X.

The trivial partitions into singleton sets and the partition into one set X itself are block systems. A transitive G-set X is said to be primitive if contains no nontrivial partitions.

Blocks in meteorology are large-scale patterns in the atmospheric pressure field that are nearly stationary, effectively “blocking” or redirecting migratory cyclones. They are also known as blocking highs or blocking anticyclones. These blocks can remain in place for several days or even weeks, causing the areas affected by them to have the same kind of weather for an extended period of time (e.g. precipitation for some areas, clear skies for others). In the Northern Hemisphere, extended blocking occurs most frequently in the spring over the eastern Pacific and Atlantic Oceans.

On the Internet, a block (also sometimes referred to as a banhammer) is a technical measure intended to restrict access to information or resources. Blocking may be implemented by the owners of computers using software. Some countries, including China and Singapore, block access to certain news information. In the United States, the Children's Internet Protection Act requires schools receiving federal funded discount rates for Internet access to install software that blocks obscene content, pornography, and, where applicable, content “harmful to minors”.

Blocking may also refer to denying access to a web server based on the IP address of the client machine. In certain websites, including social networks such as Facebook or editable databases like Wikimedia projects, users can apply blocks on other users (based in either IP number or account) to prevent them from performing certain actions. Blocks of this kind may occur for several reasons and produce different effects: in social networks, users can unrestrictedly block other users, typically by preventing them from sending messages or viewing the blocker's information or profile.

A block of the periodic table of elements is a set of adjacent groups. The term appears to have been first used by Charles Janet. The respective highest-energy electrons in each element in a block belong to the same atomic orbital type. Each block is named after its characteristic orbital; thus, the blocks are:

• s-block
• p-block
• d-block
• f-block
• g-block (hypothetical)

The block names (s, p, d, f and g) are derived from the spectroscopic notation for the associated atomic orbitals: sharp, principal, diffuse and fundamental, and then g which follows f in the alphabet.

The following is the order for filling the "subshell" orbitals, according to the Aufbau principle, which also gives the linear order of the "blocks" (as atomic number increases) in the periodic table:

For discussion of the nature of why the energies of the blocks naturally appear in this order in complex atoms, see atomic orbital and electron configuration.

The "periodic" nature of the filling of orbitals, as well as emergence of the s, p, d and f "blocks" is more obvious, if this order of filling is given in matrix form, with increasing principal quantum numbers starting the new rows ("periods") in the matrix. Then, each subshell (composed of the first two quantum numbers) is repeated as many times as required for each pair of electrons it may contain. The result is a compressed periodic table, with each entry representing two successive elements:

A block is a defensive tactic in chess in response to an attack, consisting of interposing a piece between the opponent's attacking piece and the piece being attacked. This type of blocking will only work if the attacking piece is a type that can move linearly an indefinite number of squares such as a queen, rook, or bishop and there is at least one empty square in the line between the attacking and attacked piece. Blocking is not an option when the attacking piece is directly adjacent to the piece it is attacking, or when the attacking piece is a knight (because knights "jump over other pieces" and cannot be blocked). When an opponent's attack on a piece is blocked, the blocking piece is to some extent pinned, either relatively or absolutely, until a future move by either side allows it to be unpinned.

A check on a king by an opponent's queen, rook, or bishop can sometimes be blocked by moving a piece to a square in line in between the opponent's checking piece and the checked king. Note that the blocking piece is then absolutely pinned to the king by the attacking piece.

Another type of interposing in chess can involve placing a piece between two opponent's pieces where one of those pieces is protecting the other, or they are both protecting each other. This chess tactic can be called interference.

Block is an Australian term for a small agricultural landholding. Block settlement has been used by Governments to encourage decentralization and during financial depressions to give families of unemployed workers an opportunity (frequently illusory) to become primary producers. It may also refer to a lifestyle choice or "hobby farm" for those with an independent source of income.

In parts of Australia, parcels of land of around were allocated by Government to working-class men at nominal rent during the depression of the 1890s with the object of giving them work and, potentially, a source of income. Some eventually prospered, but those on marginal land were doomed to failure. Proponents of the "block system" included George Witherage Cotton. Holders of such allotments were referred to as "blockers" or "blockies".