VGA (a TLA for Video Graphics Array) was introduced by IBM in 1987 for its PS/2 line of computers. It was released at the same time as MCGA, and supports all MCGA modes. It offers all screen modes used by previous graphics adapters, (MDA, CGA, EGA, PGA, and MCGA) as well as the standard 640x480x16 display mode. While it can emulate these screen modes, it is not compatible with earlier monitors, as they use digital signalling with TTL logic, whereas VGA is transmitted in analog. Also, VGA monitors connect through a 15-pin D-type connector, while the earlier graphics adapters used a 9-pin D-type connector.
VGA connector pinout
the pinout is the same for MCGA and SVGA, as well.

1 Red 1 5 2 Green ____________ 3 Blue / o o o o o \ 4 Gnd \ o o o o o / 5 Gnd \o o o o o / 6 Red Gnd ---------- 7 Green Gnd 11 15 8 Blue Gnd 9 Not used 10 Gnd 11 Gnd 12 Not used 13 Horizontal sync 14 Vertical sync 15 Not used