http://lmgtfy.com/?q=correspondence+chess
help me

It's called "online" here or "turnbased" or "daily". For some reason Erikspeak doesn't include the word correspondence.

what is correspondence chess
By the name of it, it should be obvious, really. Also called postal chess.
The two players play chess by exchanging moves like letters.
I think on this site the minimum is 1day/move, and the most is 14days/move.
It makes for really interesting and long games.
Sometimes you can even make friends, and actually exchange long letters, like the way they originally played this kind of chess back in the day, long before the internet.
what is correspondence chess