Am I missing something? They are the exact same thing. The company decides to terminate your employment contract, as opposed to you making the decision.
"For cause" usually means something much worse than "poor performance". That term is generally harassment, fraud/embezzling, other illegal acts, gross insubordination, etc.
Being fired because you are performing poorly in your job is, crazily enough, not "fired for cause" but simply "fired".
Being fired "for cause" usually makes one ineligible for unemployment income.
Thanks. I used the "for cause" a little sloppily. A sales person who misses quota will still be able to get unemployment benefits, while another salesperson who likes to walk around the office without pants will probably not.
Additionally, being laid off usually results in at least a respectable severance package. Being fired generally means you only get the minimum legally owed to you.
Being one of 14,000 employees let go because they chose to eliminate that entire half of the company doesn't necessarily mean anything. Being one of four engineers chosen to be let go from a team of 20 can say something about your skill level.
The practical difference is the ability to collect unemployment benefits. If you're fired you may not be able to collect benefits depending on the situation and state where you live.