What is Bitcoin mining?
Mining cryptocurrency is like mining gold or silver at a mountain. When you start digging into a mountain it's relatively easy but over time you will need more advanced equipment as the process gets dangerous and difficult. Mining cryptocurrency is basically solving mathematical problems and these problems get difficult with time. As the difficulty increases the miner would need fast and reliable technology.
How to start mining?
To start mining you need hardware (ASCI for Bitcoin and GPU for other cryptocurrencies) and electricity. Setting up a mining rig is expensive and requires cheap electricity so instead people join mining pools or mining clouds.
What is a mining cloud?
A mining cloud is website that offers mining services. Its an alternative for people who would like to mine without worrying about hardware, electricity and maintenance. The most popular mining service is
http://genesis-mining.com