If you are looking for a way to make additional space on your existing work desk, this is an excellent way. Put your VESA compatible monitor on an adjustable arm.
This one from Amazon Basics is a great choice, very sturdy and well built. It attaches to the desk using a very secure C-clamp, but also has an option for mounting if you have a mounting hole in your desk top.
Again it most cases it requires a VESA compatible monitor. I have a Samsung 4k monitor which isn’t VESA compatible, however someone made an adapter for it. It supports monitors up to 32 inches and 25 lbs.
It’s amazing how much difference having your monitor mounted on an arm makes in regards to desk space.