What does per mean?
Per is a preposition that has several meanings. Probably its most common use is almost invisible—in the abbreviation “mph (miles per hour),” where it means “each.”
It’s commonly used in newspaper reporting to mean “according to” (e.g., “The President has been kept informed, per sources close to the Oval Office”).
Per is often found in the phrase per our conversation in emails and letters (e.g., “Per our conversation yesterday, could you let me have the new draft proposal by Friday, please?”).
Per can also refer to how often something happens (e.g., “Take one tablet once per day”), or it can have the meaning of “every” (e.g., there are more cafes per square mile than in any other city”).
Per is also commonly used in the phrase per se to mean “intrinsically” or “by itself” (e.g., “The film isn’t bad per se, but it can’t compare to the book”).