Definition of log in

The phrase "log in" originated in the context of mainframe computing, which became popular in the late 1950s and 1960s. In this era, computers were massive machines that could fill entire rooms, and they were used primarily by large corporations and government agencies. To protect the privacy and security of these sensitive systems, users were required to identify themselves before being granted access. This process involved physically inserting a card, called a "logical card" or "operator card," into a console known as a "logical console" or "console operator station." The term "log in" was coined as a shorthand way of describing the process of logging in using these cards. It eventually became the standard terminology for any system that required user authentication, including personal computers, smartphones, and web-based applications. Over time, the physical devices used for logging in have become obsolete, but the term "log in" has persisted as a widely understood and convenient way to describe the process of accessing a system or service by providing a unique identifier, such as a username and password.