There are two companies hidden beneath the name "Namco":
(1) An old Japanese arcade game manufacturer, founded in 1955 under the name of Nakamura Seisakusho. it changed name into Nakamura Amusement machine Manufacturing Company in 1971.
They developped many arcade game titles and games for home systems.
In 2005, they became a child company for Namco Bandai Holdings, and in 2006 the name changed to Bandai Namco Games (in the west: Namco Bandai games).
(2) A new Japanese game center (arcade hall) and theme park company, founded in 2006. Namco is the amusement manufacturer part of old Namco that broke free when the firms were fused into Namco Bandai. Namco is still a daughter company of Namco Bandai Holdings.
As both companies use the same logo, they are often confused with each other, but they are two different companies.