The phrase "rate of fire" refers to the number of shots that can be fired from a weapon in a given period of time. It is typically measured in rounds per minute (RPM) or cycles per second (CPS). The rate of fire can vary depending on the type of weapon, its design and caliber, as well as the skill of the shooter. A higher rate of fire can increase the effectiveness and efficiency of a weapon, but it can also lead to overheating or reduced accuracy.