The document summarizes the history of educational technology from early tools like cave paintings to modern technologies. It describes how early films, radios, overhead projectors, and instructional television were adopted in schools in the early 20th century. It then discusses how computers began being used in education in the 1950s-1960s and became widespread in schools by the 2000s, with most schools having internet by that time. The document outlines how educational technology has evolved from simple tools to now enable designing, delivering, and managing instruction globally.