Convection roasting is when you use the probe, convection bake is with out probe. Basically anything you wish to keep moisture in is convection, anything you want to take moisture out you use non-convection. So a chicken is with convection and a baked potato is without

In convection roasting the heat source comes from a heating element in the top of the oven. In convection baking the heat comes from a heating element surrounding the fan in the rear of the oven.

Your owners manual should tell you which function to use for what particular food you are cooking.

WOW.. this wasn't my post or question but I just learned something I didn't know. Thanks all... I love this forum!

You can check out this article about cooking a turkey in a convection oven: http://www.appliance.net/2008/roasting-a-turkey-in-your-convection-oven-917

Thanks to paddy_99 for the helpful clarification on convection roast vs. bake.

Have to politely disagree with guadalupe - because of the fan blowing, convection will actually dry out what you are cooking more than conventional cooking (consider that an oven with a fan that operates with no heat or very low heat is called a "dehydrator"). Many foods like baked potatoes and chickens will cook beautifully with either convection or conventional cooking.

Some important advantages to convection cooking are:
1. More even cooking - the movement of hot air minimizes hot and cold spots (It doesn't always completely eliminate them though).
2. Better browning - meats, baked goods and even vegetables will brown more quickly, more completely and more evenly.
3. Faster cooking - because the moving air transfers heat more efficiently, food cook can cook in about 2/3 of the time (give or take depending upon oven temp and size/surface area of what's being cooked).

Some important disadvantages of convection cooking are:
1. Food can brown and/or burn too quickly.
2. Foods can get dried out or lose too much moisture. commercial/banquet chefs rarely cook large roasts using convection because the moisture loss results in "shrinkage". Not only is the meat less juicy, but it literally shrinks so the portions look smaller and you have to serve more (thereby eating into your profits) or customers think you're shorting them.
3. An undesirable crust can form on items like custards and cheesecakes are more likely to crack.
4. Pie crusts are more likely to burn on the edges before the pie is completely cooked (particularly true for deep-dish).
5. Some foods are delicate or light enough that the blowing air can actually interfere with their cooking or blow them out of the pan and make a mess.

Re smaller roasts and poultry (except large turkeys):
Convection can be a good method because the food browns quicker so the desired browning occurs without overcooking it (overcooking dries the food out much more than a small amount of of moisture loss during a quicker cooking time. I personally like a combination method of getting the desired browning using convection and then switching to lower temp conventional cooking to maintain juiciness.

Convection is also swell for:
- roasted potatoes, roasted vegetables, gratins
- cookies, muffins, and baked goods where you want a crisp crust like puff pastry, baklava...

Convection is not so swell for:
- larger quickbreads, cakes and many breads where a hard crust will form on the outside before the item has completely risen resulting in an unpleasantly dense product
- Keeping food like french toast or pancakes warm after cooking - because it will dry them out and toughen them.

Happy Cooking - Experiment and have some fun!