What do brk and sbrk mean?

Question

As long as I know what the Unix brk system and the sbrk function sbrk , I have no idea what they are for. Can anyone enlighten me?

Answer 1

It comes from the "meaning of the gap."

I quote: “The change occurs by resetting the process interrupt value and allocating the appropriate amount of space. The gap value is the address of the first location outside the data segment.”

(source: http://www.s-gms.ms.edus.si/cgi-bin/man-cgi?brk+2 )