Each type of video port, except VGA, is digital. The VGA cable port is analog, providing an image quality lower than that achieved through digital ports. The difference between digital and analog ports is at the resolution level and not at the image quality level; in other words, the image quality displayed at the 1920 × 1080 / 60Hz resolution through the HDMI port will look exactly the same when displayed through the DVI or Display port at the same resolution.
VGA port (Video Graphics Array)
VGA is one of the older connectors and it can only transmit analog signal, which can affect the image played on the new LCD monitors. VGA ports are found on older systems. Not all recently manufactured TVs, computers, monitors and laptops have a VGA port.
Digital Visual Interface (DVI) port
DVI is mainly used to connect monitors to computers. Televisions and laptops are not so often equipped with a DVI port. DVI plays digital signal, the image quality is very good, similar to the quality provided by the HDMI port. DVI cables usually do not carry sound (there are some exceptions)
High-Definition Multimedia Interface (HDMI) port
HDMI is used in a very wide range of electronics, being the most popular video port. The video signal can be transmitted over long distances without the need for a signal amplifier and it is possible to connect more monitors to a computer using a single cable.