Introduction from the official website:
The Internet Computer (ICP) is a World Computer that provides a complete IT stack on which any online system or web3 service can be built in a fully decentralized form, 100% on-chain. ICP is the only blockchain with smart contracts that serve web experiences, create transactions on other chains, directly integrate with web2 APIs without oracles, and run 20,000x more efficiently. No centralized cloud. Simply powered by breakthrough Chain-key Cryptography.
The Internet Computer Protocol runs on servers with standardized hardware, which we call nodes. Nodes are distributed globally and hosted in independent data centers to ensure fault tolerance and decentralization. Nodes are grouped together into subnets, where each subnet constitutes its own blockchain that makes progress independently of the other subnets, resulting in unprecedented performance and scalability in the blockchain space. All subnets are connected and orchestrated by the Internet Computer Protocol to give rise to the Internet Computer.
The IC improves and evolves at a rapid pace through regular and seamless roll-outs of software updates that boost performance, iron out bugs, and introduce entirely new capabilities. Continuous hardware upgrades, adding nodes or subnets, make the IC scale virtually without bounds — scaling the IC is always possible by adding additional nodes.
Some information in this note come from the following external links: