The magic of Equestria is everywhere and within everything; it is a part of the inherent natural laws which govern and control the processes of the world. Magic is universal in its elemental state, taking no definite form or shape. How the magic of Equestria is channeled determines its properties, be it through talents or specialized spells. At its foundations, magic is the same for everything. However, each tribe of ponies (and the numerous other sentient races of the world) have found methods to express and utilize it in different ways.
The root of all magic is the same, and only through the progression of time has it grown to be more specialized in the groups that use it. The methods of spellcaster are always changing and evolving, adapting as it is used to suit required needs. As magic being an underlying homogeneous force within the world of Equestria, some member of a group may have talents or skills which sit outside the norm. For example, while pegasi are those which general share talents of weather control and manipulation, a unicorn may share a similar talent (manipulation of water, or control of the wind). Another instance may involve a pegasus having a talent more closely related to that of an earth pony, such as a great affinity for fauna, or a talent for understanding the cultivation of crops.
What are ley-lines?
As magic is an elemental force upon the world of which Equestria is a part of, it can be found concentrated upon certain paths which flow about the world. These paths of magic flow through and pervade everything. As worlds might carrie jetstreams or ocean currents, the world of Equestria has similar currents of magic. Some of those which have studied the phenomena of magic to understand its physical properties have dubbed these flows of magic as 'magistreams.'
Where major ley-lines may cross, magic can oftentimes be found in greater strength and influence at these position. It is not uncommon for these areas to exhibit manifestations of magic in bizarre, or otherworldly fashion.
Ritualistic magics are those magics which are above the cast of the average user, often times taken great preparation and procedure among a large group of individuals. Examples of these forms of magic magic have been exhibited throughout history. The most recent example of such practices can be found with the bearers of the Elements of Harmony. These bearers work together, using their combined strengths in order to control the magics of these Elements, using them to banish or rebuke the evils that might threaten those of peace and order.
With the lore of Hearth's Warming Eve, it is stated that before the appearance of Princess Celestia and Princess Luna, and before the founding of Equestria, the movement of the sun and moon were controlled and balanced by the unicorn tribe. It has been stated that this was done through the collective efforts of ponies working together, combining their talents and skills to effect change. Other examples of ritualistic magic that can be included in this might be annual practices, such as the Running of the Leaves, or Winter Wrap Up. Each of these celebrations bring individuals into a group, who upon working together, are able to bring about change upon the world in great capacity.
Through these examples, how there are used is upon a case-by-case basis, but they all share a general theme. An individual pony who attempts such things would have an incredibly difficult time, no matter the amount of preparation and procedure they go through, and might even find it impossible without the help of some form of group or cooperative.
This section will be filled out in time. For now, please refer to the following links for a general synopsis of the various types of racial magics.