A string is a sequence of characters used in programming and computer science to represent text. Strings can include letters, numbers, symbols, and spaces, and they are often enclosed in quotation marks. For example, the string "Hello, World!" contains 13 characters, including punctuation and spaces. In many programming languages, strings are treated as data types that allow for various operations, such as concatenation (joining strings together) and slicing (extracting a portion of a string). Common functions associated with strings include finding their length, converting them to uppercase or lowercase, and searching for specific characters or substrings within them.