String is the most common data type found in almost any programming languages. A string is a group of characters such as letters, numbers or symbols. It is declared using the string keyword. Strings are very important if we want to store different kinds of information such as our name, address, gender, or email. We use strings to prompt the user with information or alert them with error messages. Also, with the help of regular expression in C#, we can create patterns that much specific strings. Regular expressions are typically used in the validation of information. The upcoming lessons shows you different characteristics of a string and the methods you can use to manipulate it.