1. It's been a long time.

2. It's been a while.
3. I haven't seen you for a while.
4. Long time no see.
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Are they all the same in meaning?
Does 'a while' mean ' a long time' or 'a short time'?

1 answer

All mean about the same thing, yes.

'A while' is indefinite, but usually implies a long time.