Cosmos is the "internet of blockchains" and aims to solve the "most pressing problems" of the blockchain industry. It is trying to build an ecosystem of independent, parallel blockchains that can cooperate with each other. By offering an ecosystem of interconnected blockchains, it provides an alternative to the slow, expensive, unscalable and environmentally damaging proof-of-work protocol that Bitcoin also uses.
Other goals of the project include simplifying blockchain technology for developers and making decentralized applications available. By using the Interblockchain communication protocol, it makes it easier for blockchain networks to communicate with each other, preventing industry fragmentation.
It uses a proof-of-stake algorithm. Validator nodes that stake a larger amount of ATOM tokens are more likely to be selected to verify transactions and receive rewards. Nodes that are found to be acting unfairly may be penalized or lose their staked tokens.