The key is commonly found on desktop and laptop keyboards. The key has the opposite effect of the End key. In limited-size keyboards where the key is missing the same functionality can be reached via the key combination of . Its standard symbol from ISO/IEC 9995-7, ie., is used on some full-size keyboards instead of a possibly localized text label.
In modern Microsoft Windows text editing applications, it is primarily used to return the cursor to the beginning of the line where the cursor is located. When the text is not editable, the key is used to return to the beginning of the document; this can also be done in editable text if the key is pressed along with. The key can also be used to select all the characters before the cursor in a certain line if pressed along with in selectable text.
Only full-sized Apple keyboards have a key. On most macOS applications, the key works like the original on UNIX in the days of dumb-terminals, where Home moves to the start of a document. When the key is pressed, the window scrolls to the top, while the caret position does not change at all; that is, the key is tied to the current window, not the text box being edited. On Apple keyboards that do not have a Home key, one can press for the Home key functionality described above. To get the same result as the Windows platform, one can press . An application can also be used to change this behaviour.
In Linux, the key has basically the same functionality as it does on Windows. It returns the cursor to the beginning of the line in editable text, and otherwise scrolls a scrollable document to the beginning. Also, like Windows, the key can be used to select all the characters before the cursor in a certain line if pressed along with in editable text.
Non-GUI applications
In older screen-oriented, text-based applications, the user often accessed the "screen" they wanted through a series of menu screens with numbered options. The key took the user to the "top" menu screen.
