A verb expresses an action or state.
Latin verbs change their endings according to mood, voice, tense, person and number.
Verbs are grouped according to the forms of these changes. A verb group is called a conjugation. There are four main conjugations (1st-4th) and a pseudo-conjugation (sometimes called “5th,” “mixed” or “3rd/4th”). Verbs which fit into one of these conjugations are called regular verbs.
There are a small number of irregular verbs in Latin. The forms of these verbs need to be known especially well, since they appear frequently.
Verbals are nouns and adjectives derived from verbs. They can have some properties of a verb (e.g. tense and voice) but are not constrained by person or mood (and so are also known as non-finite verbs).