Agni means fire. Agni is the fire god in Hindu culture.
Agni is a major God in the Vedas which is invoked along with other vedic God like Indra.
The first hymn of Rigveda is dedicated to Agni. Devotees offer the offerings to the Gods through Agni in hawan rituals.
Thus, Agni also acts as a mouth of the Gods. Agni is one of the five elements along with space, water, air, and earth.
Agni is also reverred as a guardian deity of the direction.