Knives are better than scissors for some uses. Unlike a knife, scissors have two sharp edges.
Some types of scissors, like children's scissors, are not very sharp. Children's scissors are often protected with plastic. These are called "Safety Scissors".[2]
Scissors can be made for left-handed or right-handed people. Using scissors made for the wrong hand is very hard for most people.
There are many kinds of scissors used for cutting different materials and shapes.[3][4][5]