information; spheres

I thought I'd make a section just for these glowing balls, because they play such an important part in the games.

Right. There are many types of spheres. In FFX there were the Jecht Spheres (which taught Auron his overdrives), movie and music spheres, and so on. Now, basically all these pretty things do is record images and sound. Hence, movie and music spheres. In FFX all the cool FMV's you've seen can be viewed in the sphere theater, but first you had to focus on the movie memories, so that they could be captured. Well, Tidus had to, at least.
Then there are the spheres for your sphere grid. So spheres can increase your battle stats and skills also. These are often dropped by fiends.

In FFX-2 the spheres get more screen-time. There are these 1000 year-old movie spheres that tell about Spira's history, not to mention the dresspheres. Now these are useful little buggers invented by Shinra, the genius. The spheres have captured the memories of a person, and YRP can use these memories to learn new fighting techniques.
Of course, there is the sphere network, which is also invented by Shinra. It shows that with a little extra technology you can speak real-time through them.

Now that we got that cleared up, spheres are made in Macalania woods. Remember the little spring just before the freezing coldness that is the pathway to Macalania Temple? Where you fought the big and nasty Spherimorph-what's-it's-name? Well, spheres are made in there. Although in X-2 the woods are dying, so I wonder what happens to all the spheres...?