Definition

Key-value pair is a phrase used to refer to any data set that has two parts, an identifier known as a key and a value being the data captured.

Use Cases and Examples

key-value pairs make it easy to organize data into groups. There are many data stores and data structures that store information as key-value pairs. For example the JSON data structure

[
   {
      "name":"Ama",
      "age":23
   },
   {
      "name":"Kofi",
      "age":24
   }
]

In the above example one of the objects has name as the key and the value being Ama.

Some databases that implement key-value pair structures include redis and memcached. Because of the simple nature of key-value data stores they are mostly used to store simple data sets like cached data and queue values.