The CDL points system is used to create a shorthand way of monitoring your driving record. When you get a moving violation while driving your commercial vehicle, you are assessed a certain number of points for that moving violation. The exact number of points that you may be assessed varies by state, however the points are usually around 1.5 to two times the amount of points you'd get for the exact same violation if you committed it while driving your own car. The points also vary depending on the severity of your offense; driving a few miles over the speed limit, for example, may get you only 2 points, while something like reckless driving could get you 5 or more points.
As you get points for violations, these points can add up. They will typically remain on your record for a set period of time- usually a year or two- and any points you get during that time will be cumulative. So, if you get a moving violation and get 2 points and then another moving violation and get 3 points, you will then have 5 points on your license.
Having points on your license can disqualify you from getting a job, depending on the policy of the company who you are trying to work for. It can also result in you having your commercial drivers license either suspended or revoked if you acquire enough points within a given frame of time.
To avoid the potential consequences of too points points on a CDL, if you do get a ticket, hiring a lawyer to help you either defend yourself or plea bargain to avoid points, is often a wise investment.