The most common trim package you’ll see on an early Bronco is the Sport. It was offered starting in 1967 so had a longer run then the other trim packages like the Bronco Ranger and Bronco Explorer. Think of the Sport as the base package that other trim packages used to add on to. The true “base” of course was no trim package at all, but the Sport was the most common.
The Sport was an aesthetic package and had nothing to do with performance. It consisted of a lot of “bright” parts, which is what Ford literature used to describe chrome.