A Beginner's Guide to Azur Lane

In Azur Lane, you acquire Shipgirls, which are a combination of a manga girl and a ship of war -- aircraft carriers, submarines, battleships, cruisers, and other such ships. You acquire Shipgirls, equip them, and level them through Combat and Missions. Along the way, you also enhance the shipgirls and the gear. Some shipgirls can also receive Retrofits.

You can also [[marry|Wedding] your Shipgirls. The tutorial does a good job explaining the process. Married shipgirls gain slight advantages and improve the aesthetics of the game.