Sectioning an orange means :
Removing all unwanted elements -- skin, white pith, and membranes -- and leaving only the juicy parts. Why would you bother with this fussy technique that yield less fruit than peeling, and separating into segments? Because sectioned oranges taste much better on top of fish, salads, and desserts, and they brown better under the broiler. Have you noticed how the oranges and tangerines that come from cans have no membranes? Believe it or not, it's not hard to do that at home. The reason you wouldn't just use canned oranges is that the fresh ones taste so much better. All you need to produce those glistening nuggets is a knife with a narrow blade and a little patience.
Step 1: Cut off the top and bottom of an orange.
Step 2: Set the orange on a cutting board flat side down, and cut off the skin and all of the white pith in curvy strips. You'll have to cut off a little of the juicy part too to make sure no white pith remains.
Step 3: Continue working your way around the orange until no skin remains.
Step 4: Hold the orange in the palm of one hand and the knife in the other hand. Choose a section that you are going to free. Run a knife on the right side of the section next to the right membrane, and then on the left side of the section next to the left membrane.
Step 5: Loosen the section and remove it from the orange.
Step 6: Continue removing the rest of the sections folding empty membranes to one side like pages of a book.
Ta-da -- you have a sectioned orange!