COMDEX was a computer expo trade show held in the Las Vegas Valley of Nevada, United States, each November from 1979 to 2003. It was one of the largest computer trade shows in the world, usually second only to the German CeBIT, and one of the largest trade shows in any industry sector. COMDEX exhibitions were held in many other countries from 1982 to 2005, with 185 shows altogether. The first COMDEX was held in 1979 at the MGM Grand, with 167 exhibitors and 3904 attendees. In 1981, the first COMDEX/Spring was held in New York City.

CeBIT was a computer expo which, at its peak, was the largest and most internationally representative. The trade fair was held each year on the Hanover fairground, the world's largest fairground, in Hanover, Germany. In its day, it was considered a barometer of current trends and a measure of the state of the art in information technology. It was organized by Deutsche Messe AG.