Kailua lies in the Koʻolaupoko District on the windward side of the island of Oʻahu.

In the Hawaiian language Kailua means “two seas” or “two currents”, a contraction of the words kai (meaning “sea” or “sea water”) and ʻelua (meaning “two”); it is so named because of the two lagoons in the district or the two currents which run through Kailua Bay.

Kailua is primarily a residential community, with a centralized commercial district along Kailua Road. Wikipedia