How is the help file is being use?

Eg SET HELP to MYFILE.HLP

is MYFILE.HLP a straight text file or need to be in some format??

How is the WhatThisHelpID property being use in a form and whoa is it match with the .HLP file?

PS: I am learning to use the HLP file, and when I read the help documentation, I am lost.....


Thanks you