"Tuxedo" may be used to describe a type of semi-formal dress also known as black tie, or more specifically, the jacket worn with black tie attire. In some parts of the world a tuxedo is known as a dinner jacket.
There is no strict convention governing what precisely comprises a tuxedo, given the relatively informal nature of it as a dress code. Most commonly a tuxedo is made up of a black coat with lapels, black pants, a black bow tie, black socks, black shoes, a black cummerbund, and a white shirt. In some parts of the world it is acceptable to wear a white coat--usually in hot climates, or during the warmer seasons of the year.
Novelty tuxedos are available in a wide range of colors, most popularly pink and baby blue, but these should not be considered appropriate for a semi-formal occasion. Many people wear adornments with their tuxedos, such as fancy cufflinks or handkerchiefs in the breast pocket, and in most circles this is considered perfectly acceptable.
While the breast shirt of a tuxedo is normally a pure white, some care should be taken to compliment the color of the date's dress. This is considered particularly important in weddings, when an inappropriately white shirt can cast the wrong hue on the bride's dress. In this instance it is acceptable to choose an off-white shirt similar to that of the partner's dress.
Good tuxedos are made of wool, while polyester or wool-polyester blends are generally considered sub-par. Thread count varies from worsted wool at 60-75 threads per inch, all the way up to 120 threads per inch, by fine names such as Lubiam and Andrew Fezza. The number of buttons on the tuxedo is a matter of personal preference; many people consider more buttons to appear more fashionable, but a single or dual buttoned jacket is much more traditional in appearance.
A decent tuxedo may be rented for under $100 (US dollars) in most cities, though for the best results a tuxedo should be custom fit to the wearer. Preparations for a tuxedo should start at least two months in advance, and conventional wisdom holds that if you plan on attending black tie events more than three times a year you should own your own tuxedo.
While many people consider tuxedos to be formal attire, it is important to note that they are in fact a semi-formal alternative to the more proper white tie dress. White tie includes a black full coat with tails (as opposed to a short coat), black braided pants, black socks and shoes, a black top hat, a white bowtie, a white cummerbund, a white shirt and collar, both stiffened, and an overcoat. Tuxedos were adopted primarily as a relief from the high-maintenance required for white tie attire, particularly the starching of the undershirt. In addition to the handkerchief and cufflinks often seen with tuxedos, white tie may also include a cane and white dress gloves.
As traditions in the West evolve, the prevalence of white tie events is rapidly giving way to events in which a tuxedo is the preferred form of dress. Only a few events at the highest strata of society require anything more than a tuxedo, which is easily rented at a local shop.