The "Colossus" refers to a series of early electronic computers developed during World War II. Built at Bletchley Park in the United Kingdom, it was designed to break the German Lorenz cipher, which was used for secure military communications. The first Colossus was operational in 1944 and marked a significant advancement in computing technology. Colossus utilized over 2,000 vacuum tubes and was capable of performing thousands of logical operations per second. Its development was led by Tommy Flowers and his team, and it is often considered one of the first programmable digital computers, laying the groundwork for future computing innovations.