What does "buffer" mean?

[bPrice]

I have read Wiki, I have read a lot of other definitions. Still I feel very confused every time I come across this word.

I am no computer science professional. Hope the community can help me out, give me some figurative explanation to help me understand.

Thank you so much

[keskiverto]

It is like your wallet.
You can put money into wallet. The wallet cannot hold more than some amount.
You can take money from the wallet, but not more than there is.
The puts and takes can happen independently of each other (as long as wallet isn't full or empty).