The verb is arguably the most important part of the sentence. In fact, many Spanish verbs can form a complete sentence all by themselves: ¡Siéntate! (Sit down!) Caminan. (They are walking.)
Spanish verbs contain much more information in their endings than English verbs, but the flipside is that there are many more endings to choose from. This is why many non-native students have difficulty mastering Spanish verbs. In English, there are just a few basic forms and endings, like the -ed ending to represent past tense. In Spanish, each verb has as many as 106 forms.
Fortunately, verb conjugations follow a set of rules with only a few exceptions, so being able to conjugate many verbs doesn't actually involve memorizing conjugations for each one separately.