What is "duha"

The Duha prayer is the voluntary, Islamic prayer between the obligatory Islamic prayers, Fajr and Dhuhr. The time for the prayer begins when the sun has risen to the height of a spear, which is fifteen or twenty minutes after sunrise, until just before the sun passes its zenith ( zenith is when the time for dhuhr prayer begins). When prayed at the beginning of its time it is called Ishraaq prayer.