In this article Morgan Fogarty guide us on how to write a very simple Smart Contract in the Solidity programming language.
She explains basic concepts on this subject like that contracts are declared with an uppercase first letter and they act like classes in Ruby, Java and Python. Solidity is a statically or strongly typed language. In these languages, variable types are checked at compile time, rather than at run-time (dynamically typed). For example, if a variable is declared a string, and later we try to pass it as an integer, an error will be raised.
Smart contracts help you exchange money, property, shares, or anything of value in a transparent, conflict-free way while avoiding the services of a middleman.
Find the article here: How To: Write a Simple Smart Contract