They are whitish in color, they are round and when stretched out kind of go to a point, they can also look like a small seed, and they leave a 'snail trail'.
Are these worms you are seeing in or on your cat? Or worms that you are seeing around the house and are worried that they may harm your cat?
If your cat has the worms and you are seeing them in the litter box or stuck to your cat's butt or something, you need to take your cat to the vet for treatment. Worms that a cat has can certainly make a cat sick. See these articles:
If you are worried that worms around your house may make your cat sick, try to keep the worms out of the house if possible. You may want to put your cat in a flea and parasite preventative just to be safe. From your description, I'm not sure what kind of worm you are seeing.