The purpose of the branch predictor is to improve the flow in the instruction pipeline.

The longer the pipeline the greater the need for a good branch predictor.

But the branch predictor keeps records of whether branches are taken or not taken.

A local branch predictor has a separate history buffer for each conditional jump instruction.

A global branch predictor does not keep a separate history record for each conditional jump.

The first branch predictor is fast and simple.

So an early branch predictor simply did that.

For a more thorough description of the problems which arose, and a popular solution, see branch predictor.

Branch history table, a term used in computer science for branch predictor.

The net result is that the branch predictor has a larger effective history table, and so has better accuracy.