What does DDR3-1066/PC3-8500

[Surfertech1010]

I can't find any info on what each of these mean DDR3-1066/PC3-8500 can anyone help?

Thank you,
Surfertech1010

 

[henydiah]

read in here said jaquith :
http://www.tomshardware.com/forum/288431-30-what-ddr3-1066-8500