What does spawn() function do and how do I use it?

A basic way to put it, its an updated coroutine. I use them as basic code jumps where i can execute something at the same time.

Dont use to many of these; it can actually create lag.

So a basic example:

while true do
    wait()
    print'1'
end

print'2'

So in normal terms the print'2' will never be executed but...

spawn(function()
    while true do
        wait()
        print'1'
    end
end)

print'2'

if we do it like above the console will look somewhat like this...

--> 1 --> 2 --> 1 --> 1 --> etc

If you have any more questions let me know in the comments and i will get back with you asap