You have learned that a verb is an action word. It describes the activity in a sentence. Walk, run, swim, drive, are samples of verbs or action verbs. However, there are instances when they function to bridge the gap between the subject of a main clause and a word that describes, identifies, or refers to the subject complement. These are called linking verbs.
My brother Leon looks content. (linking) My brother Leon looks at me. (action)
Maria felt tired after the long journey. (linking) Maria felt her legs with her hands. (action)