It looks more like a bladder snail, but the shell is spiralling in the wrong direction, so it could be a pond snail. But it's not a very clear photo.
Pond snail. Shell spirals in the direction of your photo. Shell is usually a brown colour with no markings. Antennas look like yoda ears. Grows upwards of 1 inch.
Bladder snail. Shell spirals in opposite direction of your photo. Shell is usually brown colour with markings (spots). Antenna are thin and spindly. Grows to about half inch.
Whatever, they are a pest snail, and once they are in your aquarium they are almost impossible to get rid of short of chemical treatment. You can control numbers by manually killing or removing them when you see them. They thrive on leftover food, so dont overfeed your fish. Some fish and other inverts will eat them. But if you are seeing them in your aquarium they are likely in your filtration etc. If you keep on top of numbers they shouldn't cause any problems, but if the numbers get out of hand they could consume your plants.