here's a guide

Perfume (Parfum)
This consists of a 15-30% concentration of perfume essence and is the strongest fragrance available. This means that not only do you need to use less, but also that the fragrance lasts longer, typically for up to 6 hours, depending on skin type.

Parfum De Toilette
This is usually between a perfume and an EDP in strength but a few companies use the term to describe an EDT.

Eau De Parfum (EDP)
This is lighter than Perfume, with an 8-15% concentration, and so is less expensive but still has long lasting characteristics, from 3 to 5 hours.

Eau De Toilette (EDT)
This is a lighter more delicate fragrance, with a 4-8% concentration of the essence, and is therefore most suited to everyday use. It is normally less expensive than Eau de Parfum, and lasts for 2 to 4 hours.

Eau De Cologne (EDC)
This is often referred to just as Cologne and has the greatest dilution of fragrances with a 3-5% concentration of perfume essence, lasting up to 2 hours.