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.
DEMOS comes from ancient Greek, meaning democracy, and also means collective. DEMOS is mainly to provide help for more and more public chains. In the process of helping, they gather public chains.