Checkpoints. How do they work?

[Viperdream]

I didn't find anything with a search and I don't really understand this script.

So this is what I should do to get a checkpoint.
CheckPoint(string& asName,string& asStartPos ,string& asCallback, string &asDeathHintCat, string &asDeathHintEntry);

I understand everything in that one. But I don't really understand what I have to do with this one

MyFunc(string &in asName, int alCount)

I know what to fill in at the name and for count it should be. But I don't understand the count. So if a player dies. How does the game know that he has to load at that point?
Does the player have to collide with the checkpoint first? Or does the game take care of that?