Who invented the radar and when?

The invention of radar is often attributed to Heinrich Hertz, who first demonstrated the existence of electromagnetic waves in 1888. However, radar technology as a practical system was developed in the 1930s and 1940s by a team of scientists and engineers. The most significant contributions were made by Sir Robert Watson-Watt in the United Kingdom, who developed radar for military purposes in 1935, and by other inventors in Germany and the United States. Radar played a crucial role during World War II, helping detect enemy aircraft and ships, and it continues to be used in aviation, meteorology, and defense systems today.