What is visual display terminals?

Visual Display Terminals (VDTs) are devices that combine a screen and a keyboard, allowing users to interact with a computer system. They were commonly used in the past for data input and output, primarily in business and administrative environments. VDTs typically feature cathode ray tube (CRT) or liquid crystal display (LCD) screens and have become less common with the advent of modern computer interfaces and laptops. Despite their decline, the term VDT is still used to refer to any screen-based interface for computer interaction.