F/stop is the focal length you have on your lens. The lower the number is on the F/stop; you get a larger amount of light. The higher the number you go, the less amount of light you get coming in. Shutter speed is the amount of time your shutter stays open. The longer it stays open, more light is going to come in. The less amount of time the shutter has, not a whole lot of light is going to enter.
This first collage is my use of F/stop. As you can see, there is the progression from f/5, f/5.6, f/8, f/16, f/22 and f/32.
This collage is my focus on shutter speed. A big thanks to my husband for volunteering to be my objective. I shot at 1/250, 1/60, 1/4, 1″.