What exactly does a shutter speed mode do? You can set the shutter speed, and the camera will automatically resolve the aperture.
It’s like a semi-manual mode. You do half of the work, and the camera does the other half. You also set the ISO to whatever you want it to be.
For example, if you set the ISO to 400 and you want to take a photo in one or two-hundredths of a second. Your camera will automatically work out that the aperture should be 5.6. You don’t have to worry about the aperture because you are only focusing on the shutter mode.
When to use shutter mode?
A great example is if you have a fast-moving car going past your camera, and you want to capture it without any motion blur. You just set your shutter speed all the way up to a thousandth of a second and the ISO to whatever you want.
Now, you do not have to worry about the aperture because the car is coming quickly and you do not have the time. The camera will automatically adjust the aperture for you.