What is the difference between a Chevy Chevy Venture and a Chevy Ventura?

Chevy venture is a mini van, made up until a few years ago. Buick made a ventura in the late 70's, which was their version of the Nova. It is a rumor that the Nova name is an acronym for Nova Omega Ventura Appollo. Which was the Chevy, Olds, Buick, and Pontiac, respectivley, versions of the Nova.