Originally Posted by DragonLance Adventures

Abjuration magics are primarily concerned with the prevention and exclusion of particular magical and nonmagical effects, situations, or individuals, and include most spells of protection, avoidance, and repellence. Examples include protection from evil spells, spells that dispel magic, and the anti-magic shell spells, among others.

Alteration spells modify existing conditions or individuals through the infusion of magical
energy. Spells that give the recipient enhanced Strength or the ability to fly, those that transform substances (polymorph self or others) and spells that have general effects (move earth or lower water) are all alterations.

Conjuration/Summoning spells are a combination of two separate magics in variable
quantities: The conjuration part brings additional matter from elsewhere, while the summoning portion creates a duct between the caster and some greater magical power. Spells that summon existing animals or monsters in an area, bring into being on this plane extradimensional creatures (such as elementals, for example), or use such creatures' power (such as a wish or power word) are conjuration and summoning magics.

Divination spells are those that uncover information that is otherwise hidden under
normal circumstances and include spells that detect magical effects, invisibility, and the
like, those spells that predict hidden or future events, and those that place the caster in contact
with powerful extradimensional creatures but do not involve direct action by those creatures.

Enchantment/charm spells place a dweomer on the target individual or item that
radiates a magical aura. On physical items it is normally used to invest an item with magical
powers (such as deeppockets or bind), but is more commonly used to induce particular
emotional or mental states in living targets (such as animal friendship, forget, and Otto's
irresistable dance). The magic jar spell, which was originally listed as a possession spell, is
really an enchantment/charm spell.

Evocation and invocations both channel magical energy, using that energy to create
specific effects and types of matter. These effects include permanent features such as the
wall spells, forces such as the Bigby's hand family of spells, and temporary effects such as
lighming bolt or t~reball. Invocations are dedicated to a particular powerful extradimensional
being and are usually confined to clerics, while evocations involve utilizing ambient magical energy.

Illusion/phantasm spells create a false reality. This sphere includes the bulk of the spells
listed in the illusionist sub-class. Illusions alone create the apparent existence of items in
the minds of the viewers, while phantasms create a shadow reality that gives these illusions
the power to affect the viewer as if real.

Necromantic spells involve the health, hit points, or normal functioning of a living or
once-living target. Spells that increase or decrease hit points, cause or cure disease, or
restore lost souls to their bodies all are necromantic spells.