Formats and concentration
Parfum vs eau de parfum
Parfum and eau de parfum are related product labels, with parfum commonly used for a more concentrated interpretation. They do not establish a universal percentage, identical recipe or a guaranteed performance order across brands.
A HUME Fragrance buying guide

Check how the brand uses the names
A parfum may be another interpretation of a fragrance rather than the same formula with less carrier. Read the exact version descriptions and available sizes.
Compare presence separately
A more concentrated interpretation is not automatically the one that projects farther. Judge the actual fragrance instead of treating the label as a volume control.
Include preference and cost
Compare the scent you enjoy, the format you want and the final price. A higher label category does not make an unwanted fragrance a better purchase.
Try this before you buy
Write what each exact version changes in the product description before comparing the price.