What does this mean? To find out, Let's listen to an actual conversation.
A: How are you, I haven't seen you for a few years!
B: I'm doing great! It's been ages since we've talked, hasn't it?
A: It's been a long time, that's for sure.
In american English, "It's been ages" is another way of saying, "it's been a long time" or "a long time has passed" since you've seen eachother.
You may remember the words "ages" being used to talk about different periods of history, like the ice age, stone age, or bronze age. Saying "it's been ages" uses exaggeration by saying that it's been many of those long stretches of time since something has happened.
And that's English in a Minute.