I just had a look at the docs on sleep().
Where would you use this function?
Is it there to give the CPU a break in an expensive function?
Any common
One place where it finds use is to create a delay.
Lets say you've built a crawler that uses curl
/file_get_contents
to get remote pages. Now you don't want to bombard the remote server with too many requests in short time. So you introduce a delay between consecutive requests.
sleep
takes the argument in seconds, its friend usleep
takes arguments in microseconds and is more suitable in some cases.