an vs as per

an

• In each; to or for each; per. 

• Used before one and words with initial u, eu. 

• Used before a vowel sound. 

• Used before all consonants. 

• Used before /h/ in an unstressed syllable. 

• Used before /h/ in a stressed syllable. 

• The first letter of the Georgian alphabet, ა (Mkhedruli), Ⴀ (Asomtavruli) or ⴀ (Nuskhuri). 

• one 

as per

• Consistent, or in accordance, with; according to