Roasting is high-heat baking with very little moisture. Roasted foods get drier and browned on the outside by initially exposing it to a high temperature. This keeps most of the moisture from being cooked out of the food. Temperature is then lowered to cook the meat through. The flavors of both meats and vegetables are retained and enhanced by roasting. A typical roasting temperature is 425-450 °F, with an initial temperature of over 500 °F for a period of 15 to 20 minutes.
You can either roast in an oven or over an open fire. Spit-roasting is a variation where the meat is impaled on a spit and rotated as it roasts.
Once meat has been removed from the roasting environment it should be allowed to rest, this ensures that the juice inside the meat returns to the outer edges. The even distribution of juice allows each slice to retain more moisture. Un-rested meat is typically dry around the edge and over saturated in the middle, leading to a loss of moisture.