You will find that most owls tend to hop, flapping their wings to jump off the ground just a little bit. Most of the time though, owls are either roosting or sitting still atop a tall tree looking for their prey. There are some birds that walk and others that hop, though most owls fit into the latter category.
Because owls have such powerful wings, they tend to use them as much as possible. These animals usually move very deliberately and flap their wings which lift them off the ground, even if it is only a foot or two.