In simple words, the difference between Parfum, EDT, EDP and EDC is actually related to their concentration in raw materials. The more concentrated a perfume is, the more it will last on your skin.

Perfume (Parfum)
It is the strongest fragrance available, consists of a 15-30% concentration of perfume essence. This means that not only do you need to use less, but also that the fragrance lasts longer, typically for up to 6-8 hours, depending on skin type.

EDP (Eau de Parfum)
It is lighter than Perfume, with an 8-15% concentration, but still has long lasting characteristics, from 4 to 5 hours. It is less expensive than pure perfume.

EDT (Eau de Toilette)
It is lighter than EDP, with a 4-8% concentration of the essence. It usually lasts for 2 to 4 hours.

EDC (Eau De Cologne)
It is lighter than EDT, often referred to just as Cologne and has the greatest dilution of fragrances with a 3-5% concentration of perfume essence. It usually lasts for 2 hours.

Eau Fraiche
Eau Fraiche on the other hand will last for the shortest duration. It usually lasts for 1 to 2 hour.