Socket 7 is a connection unit on a computer’s motherboard, the board where all the components are soldered into the computer, that allows the central processing unit (CPU) to fit into the motherboard. The socket 7 connection was made by Intel® to replace socket 5. This piece used zero insertion force (ZIF) to help the CPU fit into the computer and also allowed for different voltages to be carried to the CPU. Socket 7 was later phased out for the slot 1 connector.
The 7 connector is a plastic piece on the motherboard that contains 321 holes arranged in a square. To connect the CPU, the user or manufacturer simply has to place the CPU over the connector and it will drop into place. The main difference between the 7 connector and the socket 5 is that the newer connector is able to deliver different voltages to the CPU. This means the computer can supply more or less power to the CPU, depending on whether the computer is doing simple or complex tasks.
CPUs made for socket 5 connectors can fit into socket 7, because they are made to be backward compatible. Socket 7 cannot fit into socket 5, though, because the 7 variety has an extra pin — 321 instead of the 320 of socket 5 — which keeps the CPU from fitting into the socket 5. This extra pin on the 7 connector is the only visible difference between the two sockets. Most pins on a CPU are electronically connected, but the extra pin has no electricity; it exists just to keep the newer CPUs from fitting into the socket 5.
Socket 7 connectors are made with ZIF technology. This means the CPU does not have to be pushed or snapped in, unlike some other pieces. The CPU simply has to be placed over the pins. This makes it easier for manufacturers to insert the CPU, and makes it easier for users to upgrade the CPU.
Intel® phased out the socket 7 in favor of the slot 1. This connector, rectangular in shape, is a complete departure from past socket shapes. Many competitors improved on the 7 connector design and power and created the super socket 7, which allowed for better memory usage and added cache to the CPU. This allowed older CPUs and CPUs with the 7 architecture to continue to be used in better computers.