Function keys provide enhanced functionality to the keyboard, making it more than just a primary tool for entering data into the computer. Each function key performs different tasks in different programs. Modern keyboards typically come with 12 function keys.
Not all programs make use of function keys, and some programs only assign commands to a few such keys. Some of these functions are common among many programs. For instance, the F1, F3 and F5 keys typically launch a help window, evoke a text field for searching content and refresh the page or window, respectively. Certain computer platforms and programs allow users to program and define the roles of function keys.
Using function keys in combination with the Alt or Ctrl keys may cause the computer to perform different tasks. For instance, pressing F4 repeats the last action performed in Microsoft Word 2000 and later versions, whereas pressing Alt+F4 in Microsoft Windows causes the active program's window to close.
Some small computers and laptops do not have a dedicated row for function keys due to size restrictions. Instead, they combine the function keys with other keys, such that users must press and hold a modifier key before pressing another key that has a secondary function.