Ethereum is a decentralized, open-source blockchain with smart contract functionality.
Ether (ETH or Ξ) is the native cryptocurrency of the platform.
Among cryptocurrencies, Ether is second only to Bitcoin in market capitalization.

Cloud mining is the process of cryptocurrency mining utilizing a remote data center with shared processing power.
This type of cloud mining enables users to mine bitcoins, Ethereum 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.