Avalanche is a layer-1 blockchain aiming to provide an alternative to the high costs and low speeds. Avalanche uses a proprietary consensus mechanism to increase transaction throughput and minimize energy consumption by validators.
Avalanche is Ethereum compatible, meaning that your wallet address on Ethereum is the same as on Avalanche. Assets can be moved back and forth between Avalanche and Ethereum using a “bridge”.
You can read more about Avalanche in the official blog.