Both the simple and the continuous formation (Lesson 24) mean, very generally, 'past time and present time together'.
I've lived here all my life.
= I was born here, I live here now.
He has been working there for five years now.
= He started here five years ago and he works there now.
How long have you known John?
= When did you first meet?
We haven't seen each other since last January.
= Last January was the last time we saw each other.
Look! The sun has come out.
So now the weather is fine.
Look! It's been snowing.
So now the ground is white.
Have you seen John?
I want to speak to him.
Help! Somebody has taken my wallet.
It's the most beautiful place I've ever seen in all my life.
They've been to Thailand hundreds of times.
Have you ever eaten snake?
They have built a new stadium.
Now it is finished.
They've been building a new stadium.
It is probably not finished.
NOTICE: Have got is grammatically present perfect but it usually has a present simple meaning (Lesson 20):
Have you got a brother called John?
= Do you have . . . ?
I've got a terrible headache.