These are complex topics and each one of them would deserve much more than just 1 blog post, nevertheless, I will try here to make as simple a possible explanation of the main concepts and how they relate to each other.
1. Eth2 and its migration from PoW to PoS (The Merge) If you had any interest in decentralized technologies and the world of Cryptocurrencies, you know about Ethereum, the second blockchain in importance, and the first one trying to become a global platform to run applications in a decentralized manner.