My understanding of the terminology as used in midwest North America:
Sacked: Term not used here.
Fired: You erred severely and you are out the door immediately and permanently.
RIF'ed (Reduction In Force): The company is currently over-staffed so those employees not essential are amicably released, sometimes with a separation package to include a small lump sum payment.
Laid Off: Pretty much the same as a RIF, but may apply to a single employee only. "Position Eliminated" is the typical excuse/reason. Connotation a bit more negative than RIFFED.
When I was young, I was fired once - for good reason. A Black Spot I truly deserved.
I have been RIF'ed at least once, and called back at least once.
I have been laid off once or twice, but never called back.
I have been laid off once with a very lucrative separation package that carried me for a few months.
I have never applied for, nor received, Unemployment Insurance payments from the State. (This was my choice. A matter of pride, I suppose?)