A small outline dual inline memory module (SODIMM) consists of a number of memory components (usually black) that are attached to a printed circuit board (usually green). SODIMMs get their name because they are smaller and thinner than regular DIMMs. The gold or tin pins on the bottom of the SODIMM provide a connection between the module and a socket on a larger printed circuit board. The pins on the front and back of a SODIMM are not connected, providing two lines of communication paths between the module and the system.
144-pin SODIMMs are commonly found in laptop computers. Each 144-pin SODIMM provides a 64-bit data path, so they are installed singly in 64-bit systems. 144-pin SODIMMs are available in EDO, 66MHz SDRAM, PC100 SDRAM, and PC133 SDRAM. When upgrading, be sure to match the memory technology that is already in your system.