For regular use, you'll want to plug the Raspberry Pi in to a visual display: a monitor or a TV.
The Raspberry Pi has an HDMI port which you can connect directly to a monitor or TV with an HDMI cable. This is the easiest solution; some modern monitors and TVs have HDMI ports, some do not, but there are other options.
For monitors with a DVI port, you can use an HDMI-to-DVI cable, or an HDMI cable with a DVI adapter. Note that the DVI standard does not support audio.
For monitors with VGA only, you can use an HDMI-to-VGA adapter. Note that VGA does not support audio.
All models of Raspberry Pi have a composite out port for connecting to analog devices, but the type of connector varies depending on the model. The original Raspberry Pi used an RCA connector, and a standard RCA composite video lead will work. Others models (Raspberry Pi B+ and later) combine the audio out and composite out on to the same 3.5mm jackplug. This requires a particular type of lead, with audio left on the tip, audio right on ring 1, ground on ring 2, and video on the sleeve. This is the same as leads used on the Zune, and on Apple devices.
More information on connecting to a monitor can be found in our learning resources section.