Black Tie is a formal dress code that dates back to 1860 in England. The Prince of Wales, later on King Edward VII, wanted a shorter, more comfortable smoking jacket that he could wear to less formal dinners as an alternative to White Tie Attire.
Black tie is still a common type of dress code today. The gold standard of black tie consists of a black dinner jacket, black bow tie, tuxedo dress shirt, and high gloss tuxedo dress shoes. Occasionally a white jacket is chosen for daytime "black tie" events and functions in warm weather - it is often referred to as "warm weather black tie".
Although the overall look of black tie is quite standardized, there are many ways to add more personal style to the outfit. Choosing a cummerbund or waistcoat, wearing dress shirts with or without pleats, choosing different collar styles, and so on are just a few examples of how to add unique style to a black tie outfit.