Usually you'll find DIP Bars as part of a Assisted Chin-Up/DIP Combo Machine. This is where you can do both assisted chin-ups and/or dips.
You can replicate this exercise assisted with your knees on the padding provided or remove it to do bodyweight versions there also, but the padding and weight on a machine will allow you to take some of your bodyweight out of the equation in order to execute this as I'm demonstrating here.
Other times, you'll see a chin up station, like in the video, with the dip bars located as part of the machine also. It's rare to find them as a stand alone feature like this CALGYM station here.
The idea is to ALWAYS keep your shoulders locked down to avoid using your traps and in turn straining them or hurting yourself in some unwanted way when you try to go beyond your abilities.
Best way to get stronger at these is using an assisted DIP machine option or bench dips which I'll demo in another video.
