Consider the following sequence of actual outcomes for a single static branch. T means the branch is taken. N means the branch is not taken. For this question, assume that this is the only branch in the program.

T T T N T N T T T N T N T T T N T N

Assume a two-level branch predictor that uses one bit of branch history—i.e., a one-bit BHR. Since there is only one branch in the program, it does not matter how the BHR is concatenated with the branch PC to index the BHT. Assume that the BHT uses one-bit counters and that, again, all entries are initialized to N. Which of the branches in this sequence would be mis-predicted? Use the table below.

Now I am not asking answers to this question, rather than guides and pointers on this. What does a two level branch predictor means and how does it works? What does the BHR and BHT stands for?