The Wrangler (also known as the YJ, TJ, JK, and J8 (Military version) as explained below) is a compact four-wheel drive in the sport utility vehicle segment produced by American automaker Chrysler under its Jeep marque. It is a successor to the famous World War II ‘Jeep’ vehicle by way of the Willys civilian Jeep (CJ) in the 1950s, later produced by Kaiser-Jeep and by American Motors (AMC). The Wrangler debuted in 1987, was revised in 1997 and again in 2007, and is still popular today. A defining feature of all Wranglers is that they continue to use live axles both front and rear like their forefather, the CJ.

From 1987 until 1992 the Wrangler/YJ was built in Brampton, Ontario, Canada. It was then built in the Toledo South Assembly plant until mid-2006, after which the plant was slowly torn down. The Wrangler is produced at Jeep’s Toledo North Assembly plant in Toledo, Ohio.

Instead, 1987 to 1995 models were sold as YJ, 1997 to 2006 models were TJ’s with a subcategory from 2004 to 2006 of “Unlimited” Wranglers known as LJ’s, and from 2007 to today as the JK. The model designations are used throughout the world in the Jeep enthusiast community to differentiate which model is being spoken of instead of using the more ambiguous term “Wrangler” and help identify specifics about Wranglers.
From Wikipedia