What is "glue code"

n. (context computing English) code that serves to connect separate parts of a program for compatibility or interoperability.

In computer programming, glue code is source code that serves solely to "adapt" different parts of code that would otherwise be incompatible. It does not contribute any functionality towards meeting the program's requirements, but instead glue code often appears in code written to let existing libraries or programs interoperate, as in language bindings or foreign function interfaces like the Java native interface, or when mapping objects to a database using object-relational mapping, or when integrating two or more commercial off-the-shelf programs. Glue code may be written in the same language as the code it is gluing together, or in a separate glue language. Glue code is very efficient in rapid prototyping environments where several components are quickly put together into a single language or framework.