Final Fantasy X - Spheres
Spheres for the Temples
Destruction Spheres: These spheres are optional during the Cloister of Trials. You must go out of your way in the Cloister of Trials to get this sphere, though. It can be exchanged in another sphere slot for some treasure. Doing this in each temple will also enable you to get Anima at the end of the game.Glyph Spheres: There is nothing special about these spheres, unfortunately. Although, you will come across them in every temple. They are mainly used to activate hidden glyphs, open doors, or to trigger an event that will expell another type of sphere.
Temple Spheres: You have a special type of sphere for each temple (Besaid, Kilika, Macalania, etc). These spheres are widely used throughout the Cloister of Trials. These spheres will be used to open the final door, open the first door, trigger events to lead to another sphere or location to get a sphere, or possibly even to obtain the Destruction Sphere. They do not do all of that, though. Sometimes they may only do one or two. Depends on the temple.
Spheres for the Sphere Grid
Power Sphere: These spheres are used on the grid to activate nodes containing basic attack and defense power ups. These can also be used to power up your weapons in customization, and can also be used to add better attributes to your Aeons.Mana Spheres: These spheres are used on the grid to activate nodes that will power up your magic stats (magic, magic defense, etc). Just like Power Spheres, these can also be used to power up your weapons/abilities and also Aeons' abilities/attributes.
Speed Sphere: Speed Spheres are used to activate the nodes that deal with speed (evade, agility, etc) on the grid to help power up your character. These can also be used to customize and power up your weapons and Aeons.
Ability Sphere: The Ability Spheres are used to activate the nodes that will teach your character abilities like Skills, Special Skills, White Magic and Black Magic. These can be used to power up your weapons to an extent, and are rarely used to power up any of your Aeons.
Luck Sphere: These spheres will turn an empty node into a luck sphere. This cannot be used to power up your weapons, but can be used to power up your Aeons.
Fortune Sphere: There is only one good use for this sphere, and that is to activate Luck Spheres. These are hard to find, so be sure to use them wisely when you do get them.
MP Sphere: This is used to turn an empty node into a MP power up sphere. But, instead of increasing the character's MP by 20, it will raise it by 40! There is no other use for this, and cannot be used to power up your weapons nor Aeons.
HP Sphere: This is the exact same thing as the MP Sphere. There is no use for this, including customizing and power ups, but it turns an empty node into a HP sphere. After using a Power Sphere, you will gain 300 HP!
White Magic Sphere: With this sphere, you can make your character learn any white magic spell on the sphere grid you wish to learn. Even if no one else has learned it yet. So if you wish to learn Holy as soon as you get one, go ahead! Besides, this can only be used on the Sphere Grid.
Black Magic Sphere: This is the same as the above (White Magic) sphere, although the effect is the opposite. You can learn any Black Magic spell on the grid. These come more often than White Magic Spheres, so you can use them more often. A wise choice would be to teach your main black magic person Ultima, because it is hard to get to unless you're willing to dispose of three Level 4 key locks.