Is Thyme A Perennial Or Annual?

Thyme tends to grow in bushes. It is a perennial. On its second year it spreads and grows up into a large bush. This plant does not have a very long life span. It has to be replanted in every 2 or 3 years. Besides, it cannot be cut heavily. It can also be rooted by its branches, bent to the ground and covered with it. If you take off the external bark layer, the bush will grow extra roots on the branches.