Socket 775 is intel's socket, designed for Core 2, and Last-Generation Pentium processors(Pentium Dual-Core, Pentium 4 775, Pentium M 755, Pentium D 775) and 775 Celerons. Socket 775 Is an LGA socket, meaning that the pins are on the motherboard, not the processor.
Replaced with higher end "Socket H" LGA 1156.