Spring Data is a set of frameworks and libraries that simplify the process of working with relational and non-relational databases in a Spring-based application. It provides a unified API for accessing different types of data sources and enables developers to write database queries and transactions in a more concise and efficient manner. Spring Data also includes support for various types of data such as SQL, MongoDB, Cassandra, and Redis. It aims to improve developer productivity and reduce boilerplate code when working with data in enterprise applications.