The Raspberry Pi does not come with DVI or VGA video, so you would need to use a HDMI to VGA cable converter for a VGA monitor, or a HDMI to DVI cable to use on a monitor with DVI video inputs.
Most older CRT Tube monitors use VGA video ports for connecting your computer’s VGA video port to the monitors VGA video port. You would need a HDMI to VGA video converter like BestDealUSA HDMI Input to VGA Adapter Converter For PC Laptop to convert the Raspberry Pi’s video to VGA.
For newer LCD flat panel monitors which have DVI, but not HDMI, a HDMI to DVI cable like AmazonBasics HDMI to DVI Adapter Cable is needed to connect the Pi’s HDMI video to your monitor with DVI. I recommend using a HDMI to DVI cable if your monitor has DVI inputs because DVI is digital instead of Analog, so the picture quality is slightly better. Plus, it is less bulky, and easier to connect a HDMI to VGA cable because you don’t need to use a VGA cable to connect to the HDMI to VGA converter, and can directly connect a HDMI to DVI cable to a monitor. You can also use the same monitor on another computer with a VGA port on the video card if the monitor also has a VGA port, and use the HDMI to VGA cable for the Raspberry Pi. But, you may need to use the built-in switcher program on your monitor to switch between VGA and DVI video connection if your monitor is not setup to Auto video detect which switch to the port when the monitor detects a video signal on the port.
You can also use the RCA video port on the Raspberry Pi Model B . You need an RCA video cable which you can use from an old camcorder, DVD player, or TV settop box. Most TVs have a RCA video port which is the round yellow port labeled video which is usually found on the back, front, or side of the TV.
If you are not using a HDMI Monitor with speakers, you would need to use the Pi’s 3.5mm headphone/speaker jack for sound/music. VGA, and DVI don’t support audio. Many HDMI monitors also don’t support sound because they don’t have speakers on the monitor.
You may also need to setup Raspbian, Rasbmc, OpenElec, and other Raspberry Pi Operating Systems, and programs like Tboplayer to play audio through the Pi’s 3.5mm headphone jack instead of HDMI audio when you are using the 3.5mm headphone jack to play audio.