A mouse connector is a dedicated socket or an interface on the computer. The invention of the first personal computer by IBM back in 1981 and its predecessors developed different types of mouse connectors.
A, Bus mouse
This was the first type of mouse connected to the PC using a bus in th early days of IBM compatible PC through a specialized bus interface implemented via ISA add-in card. An ISA card (Industry Standard Architecture) is a 16-bit internal bus of IBM PC/AT based on Intel 80286 and is backward compatible to 8-bit bus,usually term as I/O channel by IBM.
A sample of ISA motherboard with ISA add-in mouse card
B. Serial mouse
A mouse connector using a serial port with D-type 9pin male port (DB9M). Using RS-232 protocol which was used in serial ports, how data is to be transferred bit by bit from DTE (a computer terminal) to DCE( a modem).
C. PS/2 mouse
This superceded the serial connector, it is a 6-pin mini-DIN connector used for connecting mouse & keyboard to PC compatible. Back in the day, computers would normally come with at least two PS/2 ports—one for the keyboard, and one for the mouse. The keyboard port painted blue and the mouse port painted turquoise/green.
Most systems including PS/2 ports these days will come with a single PS/2 port where you can plug either a mouse or a keyboard, or use a splitter to connect both. This type of connector you need to reboot your computer to recognized your mouse and pins is fragile or worst could damage it.
D. USB mouse
The USB universal serial bus has replaced the PS/2 ports. The way USB peripherals work is that the PC will constantly check multiple times per second.
It is hot-swappable port and no need for you to reboot ot turned-off your PC since it provides power to the atatched device hence eliminating for power connection.
E. Wireless mouse
The latest mouse connection which does not use any cable wire.
The wireless option became popular in the early 2000’s, when started incorporating radio frequency and bluetooth technology.