what's exactly difference Among OEM, AAA, AA and A quality?
You have been viewed too many about AAA quality ,AA quality even SSS quality. It seems mean nothing to you because they never talk about what's exactly different among them.
Usually, AAA quality = Original LCD + Original flex cables + Copy glass.
AA quality= Original LCD + Copy flex cables + Copy glass.
A quality = Copy LCD + Copy flex cables + Copy glass
B- quality = Copy LCD + Copy flex cables + Copy glass + little defective part
OEM quality = Original LCD + Original Flex cables + Original glass.
By the way, if you see some quality like S, SSS, SSSS or AAAA quality, they try to talk about their quality is very high. Don't need to judge them because most of the sellers don't know about details about this.
The more different between High copy and OEM, You can check : How to know if an LCD replacement screen is OEM or High Copy? or What’s different quality you can tell when you test iPhone LCD?
Basically,It's about brightness and Firmness. OEM will have better advantage on those.