UNUS SED LEO is a cryptocurrency that describes itself as "the utility token at the heart of the iFinex ecosystem." It's designed to be used on the Bitfinex cryptocurrency exchange as a way of reducing trading, lending, and other exchange fees.

Cloud mining is the process of cryptocurrency mining utilizing a remote datacenter with shared processing power.
This type of cloud mining enables users to mine bitcoins or alternative cryptocurrencies without managing the hardware.
The mining rigs are housed and maintained in a facility owned by mining company and the customer simply needs to register and purchase mining contracts or shares.
Since cloud mining is provided as a service, there is generally some cost and this can result in lower returns for the miner.