computer science - I need to make sure my programming terminology is correct -

i'm trying find right words define 2 different concepts. after doing little bit of research on online computer science dictionaries, think i've found answer. need confirm it. below, have 2 concepts written down , words think describe them.

procedure - set of instructions breaks away main flow of program. once instructions complete, value returned point procedure called, , flow continues there.

thread - set of instructions not break away main flow of program. thread run along side program.

a lot of stuff language specific, i'll try 'layman' , generic possible.

they aren't definable in sense using in question. thread sort of instance of procedure executes concurrently rest of program. aren't opposites/compliments of each other.

a procedure, in general sense, sounds term function, method, subroutine, etc. block of code logically separated, , can called needed.

a thread asynchronous call procedure, , shares same memory space calling thread.

another way of putting it, have main thread, executes top bottom, calling procedures along way. called procedures/functions/methods etc still part of main thread. can spawn new thread operating system manage, has own set of procedures/commands execute (generally) shares memory space main (or calling) thread.