A lion communicates through a range of sounds, behaviors and senses. For instance, a lion communicates its readiness to mate by releasing certain smells. These are picked up by other lions using the Jacobson's organ at the roof of each lion's mouth.
A lion also communicates by using its sense of touch. A lion rubs its head against another lion's head as a greeting. Lions show affection and welcome by licking each other.
One of the major ways that a lion communicates is through vocalization. The lion is the only cat that roars. The roar has many purposes. The roar is a unique identifier for each lion. Lions often roar together, creating a sort of song. Besides promoting pride unity, the roar also warns other predators to stay away. The roar also serve to communicate an individual lion's position to the rest of the pride. This helps a mother with lion cubs to stay away from strange and harmful males.
Roaring is also an intimidation tactic between two lions. Along with this is the male's full mane of hair. It uses its mane to appear larger and more intimidating to other predators or lions that want to challenge its position in the pride.