Single-responsibility principle
The single-responsibility principle (SRP) is a computer programming principle that states that "A module should be responsible to one, and only one, actor." The term actor refers to a group (consisting of one or more stakeholders or users) that requires a change in the module. Robert C. Martin, the originator of the term, expresses the principle as, "A class should have only one reason to change".
Source: Wikipedia — Single-responsibility principle (CC BY-SA 4.0)