How does amazon work

I know this might be a noob question but how does it work exactly?

I mean do I get credit as long as they click through my link? What if I send them from a link of a hair dryer and they buy a bunch of other stuff but nothing related to what i got them to click on?

How long do I get credit for them going back in to buy somethin?

I know I can probably read up on this on the amazonasociate site but I was hoping someone had a quick answer for me.

I mean do I get credit as long as they click through my link?
Yes

What if I send them from a link of a hair dryer and they buy a bunch of other stuff but nothing related to what i got them to click on?
Yes, you will get the credit for ALL the stuff and not just that single product link that the user clicked initiallly.

How long do I get credit for them going back in to buy somethin?
24hrs