Reaction time testing is a very useful tool that measures how quickly a person responds to changes in images. It measures the time it takes for you to click the mouse (or press a key) after seeing a command. Through this test, you can compare reaction times of a person at different times or compare results between different people. This reaction speed test is not highly scientific; it's just for fun and practice.

The reaction time of an untrained person typically ranges from 200 to 300 milliseconds, while a well-trained athlete can achieve only 100 to 200 milliseconds. Therefore, the improvement in reaction speed during training is quite small.