Decred aims to build a community-directed digital currency whose security, adaptability, and sustainability make it a superior long-term store of value. It is achieving this aim by building the world's first truly decentralized autonomous organization.
Tera is a decentralized application platform. This is akin to an operating system. Tera consists of a repository of programs and data storage integrated into the Internet. The mechanism for publishing programs and data on this platform is free from censorship. The circulatory system is the blockchain.