What is the difference between commission and bonus and how does it affect personal income tax?

My employer is changing the rate as which we (sales reps) are taxed. It is at about 3 times the previous federal tax rate we used to pay. We are paid a salary bi-weekly and commission monthly. The commission is anywhere from 50 to 100% our salary. I have been taxed at the old rate for 11 years.

Commission is based on sales. The more you sell, the more commission you get. It's actually a percentage of every sale you make goes to your pay check. A bonus is just an amount chosen by your boss(es) to give to you as a present that is extra, an addition to your normal pay check.