Why is this a buffer solution

100 ml of a 0,01M CH3COOH-solution
100ml of a 0,005M NAOH- solution

Can anyone explain me why this is a buffer solution?
Thank you!!

There are similar amounts of H+ and OH- ions in the solution.

NaOH will produce OH- and CH3OOH will produce H+.

The H+ will neutralise bases.

The OH- will neutralise acids.

Therefore resisting changes in pH

because it resists a change in pH.