An Attribute value pair is a fundamental representation of data in computer systems. And its various applications. It is a good way of storing and modeling real-world data in a database. An attribute-value pair is also known as name-value pair, key-value pair, or field-value pair. Some of its applications include: e-mail, query strings in URLs, some kinds of databases, private map data, optional elements in network protocols, etc. in some applications, an attribute-value pair has a value that contains a nested collection of attribute-value pairs.