What does clinched playoff berth mean in nba?

Answer 1

This simply means that a team has enough points to ensure that it will make the playoffs and no matter what happens in terms of wins/losses by itself or teams behind it, no team with a lesser amount of points not in a playoff position, can catch them.

Answer 2

it means that the team that clinches the spot is guaranteed to play in the playoffs. not decided which place yet it can be 1 or 8.

Answer 3

It means that they are automatically going in the playoffs because their top of all standings in their conference.