The 27 Rules of Suits
“In clothing, a suit is a set of garments made from the same cloth, usually consisting of at least a jacket and trousers.Lounge suits (also known as business suits when sober in colour and style), which originated in Britain as country wear, are the most common style of Western suit. Other types of suit still worn today are the dinner suit, part of black tie, which arose as a lounging alternative to dress coats in much the same way as the day lounge suit came to replace frock coats and morning coats; and, rarely worn today, the morning suit. This article discusses the lounge suit (including business suits), elements of informal dress code.
The variations in design, cut, and cloth, such as two- and three- piece, or single- and double- breasted, determine the social and work suitability of the garment. Often, suits are worn, as is traditional, with a collared shirt and necktie. Until around the 1960s, as with all men’s clothes, a hat would have been also worn when the wearer was outdoors. Suits also come with different numbers of pieces: a two-piece suit has a jacket and the trousers; a three piece adds a vest or waistcoat; further pieces might include a matching flat cap.” read more
This is a great guide on how to wear your suits!