An S Corp, also known as an S corporation, is a business entity type that offers a lot of important tax benefits as it preserves your ownership flexibility. The S corp is also called the subchapter or small business corporation. It was a tax code that was incorporated into the law by Congress in 1958. The S corporation was created to support and encourage the creation of family and small businesses while it eliminated the double taxation issue that the conventional corporation (C corporation) suffers from.