Have an Answer?
There are so many that it is difficult to answer that question. I'm probably leaving several types out, but here are some of the major categories:
Mechanical Engineers (similar types are Aerospace, Materials, Civil, etc.) - Deal with physical systems, frequently with moving parts.
Electrical Engineers (similar types are Computer, Controls, etc.) - Deal with systems that have electrical components.
Chemical Engineers (similar types include Biochemical, Materials, Biomechanical, etc.) - Deal with chemical or biological processes.
Software Engineers (similar types include Computer, etc.) - Deal with software or firmware.
There is a lot of overlap, and I know I've left out a bunch, but it's a starting point.