Perfume is the most expensive version of any fragrance, due to the high concentration of essences that see up to 40% of the formula being pure scent. Perfume is applied sparingly and directly to the skin on pulse points (insides of the wrists, behind the ears, on the neck) for an elegant result. Pure perfume ensures that people just catch a subtle sniff of your scent when kissing you on the cheek, rather than you being engulfed in it altogether.
Eau de Parfum is the strongest form of scent usually available from beauty counters. It contains over 15% of pure essence, providing a strong scent that keeps throughout the day due to the intensity of the base notes. It's perfect for spraying on clothing and hair, as it clings to the surface to ensure you remain fragrant. Although less intense than pure perfume extract, it's easier to apply and much cheaper.
Eau de Toilette can contain up to around 10% aromatic essence. The top notes are dominant, making it refreshing when applied, but it evaporates and fades away quite quickly. Eau de Toilette is perfect for the summer, when you want an uplifting and refreshing scent to re-apply throughout the day. It's the most popular form in which fragrance is sold, mainly due to its price point and availability.
Eau de Cologne is at the bottom end of the range, in terms of both concentration and price. This tends to contain about 7% essence for a burst of fragrance, but it doesn't last long at all. This makes it a perfect scent for hot days when you need to continually freshen up and ensure you're smelling sweet rather than sweaty. It tends to be available in large sizes of up to 200ml because of its price and high concentration of water.
There's no right or wrong type of fragrance, way to wear it or price you should be prepared to pay - it completely depends on what you like a scent to be. However, Eau de Toilettes are much nicer for warmer months, providing a lighter and fresher result, whereas Parfums or Perfumes can be great for nights when you really want a fragrance to linger. Do you have a fragrance style?