Why fry rice before boiling?

My solution for ceramic flat top stove - the burner takes time to cool down after being turned off:

Frying before boiling adds flavour, but it seems to seal in the rice so it doesn't expand as much, and so releases less starch when boiling. Usually I fry first, then add the water (usually 1 part rice two parts water unless otherwise instructed) and allow it to boil - the frying before means when the rice boils it won't rise and overflow the pot. After it has boiled a bit, I turn it OFF, wait for it to simmer down, then cover with an absorbent cloth and put the tight fitting lid over the cloth - the cloth absorbs the moisture and creates a very tight lid so no steam can escape.
Then I just leave it while I do other things (making salad or something or writing this note) - and then go back to it and it's ready.

Caution - don't let the cloth trail over the stove it will catch fire, if necessary bind it over the lid - the four corners - with an elastic, or failing that just TAKE IT OFF THE BURNER TO A COOL PART OF THE STOVE - because it will continue to cook in it's own heat, with the steam trapped inside - just give it a little bit more time since you've moved it off the burner.

OK, I think it's ready, I'll go eat now. Bon appetite.

In addition to the other answers, toasting the rice first can reduce the cooking time considerably. When you toast rice first, not only are you heating your entire pan but the rice thoroughly. You are able to add your liquid and immediately begin simmering and steaming the rice.

This is sometimes called "pilaf style", though technically actual pilafs do not require the sauteeing step. It is, however, very common in pilaf and related dishes.

The main function of this is to change the composition of the starch on the surface of the rice. This reduces the starches that cross-link and make rice sticky. It helps your rice to cook up into separate grains.

While you're at it, it also adds some flavor to the rice, by caramelizing some of the starches. Plus, it adds oil, which can carry flavors of its own and help distribute fat-soluble flavors in the other ingredients.

The effect is very different from "fried rice", where the starches have already been cooked and gelatinized before frying. The goals are somewhat the same, adding browned flavors and distributing fat-soluble ingredients, but the chemical changes to the surface of the rice itself will be different.

When the rice is dry its easier to get it toasted before you boil it because it has less moisture content. Packaged rice, like Rice-a-Roni have you do this method to get that toasted flavor of the rice.