Shutter speed is the term used to describe how long your camera lets the light through the kens and hit the sensor.
It is given mostly as a fraction. 1/2 second, 1/30 of a second even faster 1/1000 of a second. You can also have full seconds or even hours for fancy stuff.
Shutter speed is another of your cameras creative controls. You can choose a fast shutter speed to freeze the action, or a slow shutter speed to allow some blur and give a sense of speed.
You are the artist you make the decisions.
Next up putting it all together ISO, Aperature and Shutter speed, how the work together to create the correct exposure..