Shutter speed exists because of something is known as your camera shutter – which, simply put, is a curtain in front of the camera sensor that stays closed until the camera fires. When the camera fires, the shutter opens and fully exposes the camera sensor to the light that has passed through your lens.
The Shutter speeds are measured in seconds, or fractions of a second. For example, a shutter speed of 1/100 means 1/100th of a second or 0.01 seconds. This is also known as the “exposure time” because it’s the amount of time the sensor is exposed to light.
Think in these terms, the shorter the shutter time is set a general example to stop fast-moving object, animal, cars start at 1/1500-2000 in good daylight will work well. if you want to show action than you want a little blur in the photo in that case you lower the shutter to be slower like try 1/25 of a second for a long time open to make the subject show some blurring.
I recommend watching this video to make the learning experience more entertaining.
SHUTTER SPEED: Master it to get the SHARPEST, CLEANEST Pictures