Here's a handy guide to the major types - or "concentrations" - of perfume.
A Quick Note on Composition
Fragrance products are composed of animal- and plant-based aromatic compounds or esters (or their man-made equivalents), dissolved in a combination of alcohol and water. The ration of scented matter (called "perfume oil" or "essential fragrance") to solvent determines whether the product is a perfume, eau de toilette, etc.
Parfum / Perfume
Parfum - also called extract or extrait perfume - is the most concentrated or purest form of a fragrance product, and is the longest-lasting on the skin. As such, it is also the most expensive. A true parfum (perfume) will contain 15 percent or more (typically up to 30 percent) of the essential fragrance.
Eau de Parfum
Only slightly less potent (and expensive) than parfum, an eau de parfum typically contains anywhere from 8 to 15 percent of the essential fragrance.
Eau de Toilette
With about 5 to 8 percent of the perfume essence, this is a light scent designed for shorter wear on the skin.
This is the feminine term used for women's eau de cologne concentrations, containing 3 percent or less of perfume oil.
Eau de Cologne
A masculine scent composed of 2 to 5 percent of the essential scent.