LLC. A type of company, authorized only in certain states, whose owners and managers receive the limited liability and (usually) tax benefits of an S Corporation without having to conform to the S corporation restrictions. An LLC is an unincorporated association, is relatively flexible and simple to set up (making it appealing for small businesses with only one owner), and allows for pass-through income taxation. LLCs were not widely used in the United States until the early 1990s.For more information, see The Difference between an S Corporation and an LLC.