Why is Azerbaijan considered landlocked despite its Caspian Sea coast?

Although Azerbaijan has a coastline along the Caspian Sea, it is classified as a landlocked country because the Caspian Sea itself is an inland body of water that does not connect to the world's oceans.12

While the Caspian Sea is the world's largest inland body of water, it is geographically defined as a salt lake rather than an ocean or a sea with oceanic access. Because neither Azerbaijan nor the Caspian Sea provides a direct link to the global maritime system, the country must rely on neighboring nations for access to international waters.3421