Code for smart contracts in Ethereum is written in a high-level language such as Serpent, LLL, Solidity, or Viper and is converted into the bytecode that EVM understands for it to be executed.
Solidity is one of the high-level languages that has been developed for Ethereum with JavaScript like syntax to write code for smart contracts. Once the code is written, it is compiled into bytecode that's understandable by the EVM using the Solidity compiler called solc.
Official Solidity documentation is available at http://solidity.readthedocs.io/en/latest/.
Low-level Lisp-like Language (LLL) is another language that is used to write smart contract code. Serpent is a Python-like high-level language that can be used to write ...
