"Sahara: which came standard with the 4.0l 242cid engine, offered the most available options, including body color fender flares, matching side steps and alloy wheels. More saharas seem to have come with an automatic transmission and air conditioning than any other trim package." -
Resource Section
A Sahara will have the "Sahara sticker" by the Jeep logo on the sides and had a line decal (I have no idea what to call this lol) from the hood to the rear. Some Sahara models came with the special green seats with the map bags. Usually one of the more expensive trims to search for and buy, especially in mint condition. The sell price is also high because of it's movie car status in the original Jurassic Park.
What makes a YJ a wrangler? I am not 100% sure on this and someone will have to correct me. IIRC it started with a wider wheel base between the axles, and the addition of making it more comfortable for the everyday person to commute on the road with, for example air conditioning and interior trim/dash.