L2 vs Optimism vs Rollups? Help!

Hello, end user here. Not a developer or miner. So I’m familiar with EIP 1559 (July) and ETH 2.0 (ASAP). However, I’ve been reading a lot about Layer-2, Optimism and/or Rollups and can’t wrap my head around the purpose/impact.

I really want to understand:

(1) what’s the difference between these 3 (e.g. impact on fees and speed)?

(2) when will each be implemented?

(3) how does each relate to ETH 2.0?

It’s perfect fine if you explain to me like I’m a 5 year old.