What are the two key innovations coming to the Ethereum blockchain with Ethereum 2.0?

Proof-of-stake and sharding. Proof-of-stake is a new mechanism to validate blocks where stakers & validators are randomly chosen and validate a block, after staking 32 Ether as leverage. Sharding is a technique which horizontally partitions data in a database. It can be used in layer-2 protocols such as rollups and helps in scalability. The Beacon chain coordinates these shard chains