Intel Socket 775
Intel was the first processor company to introduce a so-called Land Grid Array socket for the processor. Opposed to conventional processor sockets, the CPU doesn't carry pins any more, but there are 775 tiny clips on the socket. The advantage of LGA sockets is reduced electrical resistance.
Socket 775 was introduced with Intel's launch of the 915 and 925 chipsets, DDR2 and PCI Express in 2004. The first platform generation supported Celeron and Pentium 4 processors, the following 945 and 955 chipsets also support Pentium D dual core processors and you need the current 965/975 family to support Core 2 Duo, Core 2 Quad or Core 2 Extreme CPUs.