Can someone explain stroker kits

So I am looking to rebuild my 360. It's a stock late 74 build for a 75 vehicle which makes sense since I took it out of a 75 RV.

As I am looking around at engine kits, I notice a rotating assembly kit to Make a 408 stroker run about a grand to 1500. Not bad considering people rave on about stroker motors.

I know there are still the heads and other stuff but what I really want to know:

What is a stroker ? Do you increase the bore or just the stroke?

How did stroker motors come about.....why didn't the factory stroke engines in the first place?

Can a stroker run on the street?? Any other general info?? Is 408 the only size for a 360 and are there any disadvantages??

You never stated you intended purpose for this build. Perhaps a stroker is not necessary. Strokers add a minimum of $1500-$2000 in parts and can "snowball" the machine work and other peripherals. J.Rob