To connect a Raspberry Pi computer to a monitor, the best method is to use a HDMI connection, but if your monitor doesn’t have a HDMI port, the next best connection is to use the DVI port on your monitor. If your monitor has neither of these connections, it probably has a VGA port and it is therefore probably best to update your monitor to one that does have either a HDMI or DVI port or both.So you will need either a HDMI to HDMI cable to connect the Raspberry Pi computer to a monitor, or a HDMI to DVI cable to connect the Raspberry Pi computer to a monitor. You could also use a HDMI to HDMI cable with a HDMI to DVI converter on one end of the cable.
Typical DVI connector in a monitor
Typical HDMI connector
HDMI to DVI Converter
Typical VGA connectorIf a monitor only has a VGA port, update your monitor to one that has a HDMI or DVI port.
Cable ending in a DVI plug
Cable ending in a HDMI plug
These are connectors on a modern monitor.Use HDMI for a Raspberry Pi - If no HDMI use DVI - If no HDMI or DVI find another monitor.