Data types are classifications that specify the kind of data a variable can hold in programming and databases. Common data types include integers, floating-point numbers, strings, and booleans. Each type determines the operations that can be performed on the data and how much memory it occupies. For example, integers are whole numbers, while floating-point numbers can represent decimal values. Understanding data types is essential for effective coding and data management. They help ensure that data is processed correctly and efficiently. Using the appropriate data type can prevent errors and optimize performance, making it easier to manipulate and analyze data in applications and systems.