Can someone explain the purpose of embassies? I don't understand....

They allow permanent contact with another Civ. As of some version some time ago, Civs lose contact with one another after some time -- this is recovered by bringing a unit/cultural border of theirs back into your line of sigh, and prevented by having an embassy.

This prevents long-term contact with another Civ unless you or they have some sort of representative unit having their or your (respectively) units/cultural borders withing your or their line of sight. If you are confused, ignore the last sentence and start reading it again. :)

ohhh, I see.... I didn't know civs can lose contact now....

ohhh, I see.... I didn't know civs can lose contact now....

This new simple rule speeds the game by 10~15% ( :p or not, i don't really know, but you understand my point :lol: )