The word perfume comes from ‘perfumare’, Latin meaning “to smoke through”.
If you look at the bottles they will often have specific names on them. The different names of perfumes relate to the concentration of aromatics in the solvent.
eau de Cologne is 3% – 8% aromatics.
eau de toiletteis 5% – 15% aromatics.
eau de parfum is 10% – 20% aromatics.
esprit de parfum is 15% – 30% aromatics.
parfum or extrait is 15% – 40% aromatics. This is considered to be an extract.
Cologne has several contexts, a Cologne can be a fragrance from or based on the style developed in Cologne, Germany in the early 1700s. Second is the designation listed above of less concentrated versions of scents. Last is the term generally refers to men’s fragrances.
I’ve found most department stores and places like that, calling something a perfume vs a cologne makes it clear to who you’re talking to you’re looking for women’s or men’s fragrances. Sometimes in the higher end perfumeries cologne is more acknowledged as the percentage of aromatics.
Eau de toilette, translating to English as toilet is not as disgusting as it sounds. It was originally intended to be sprayed on right after taking a shower, and usually had a flowery scent.
None of these terms are precise, there isn’t any official designation of terms, amounts, or anything like that, but this should give you an idea of what you’re looking at.