Loki combines a private transaction network based on Monero with economically incentivised service nodes to create a trustless quorum based networking protocol. This protocol allows anyone to route small packets of data in an anonymous and decentralised way. The front end applications that use this packet routing system are private-by-design, and are known as Service Node Apps “SNApps”; the first of which is the Loki Messenger - a decentralised, anonymous and private messaging service. Check out Coinbureau for the complete review of Loki Coin.
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.