Ambient Magic

"Magic is around us. It flows and penetrates and ennervates and exhausts. We create it. We leave it behind. Every part of our world is made of magic, once you dig deep enough."

— Bill Weasley

An excerpt from Ars Magica by Hermione Granger

Magical Energy

When explaining magic, it was explained that magic just is; that it is the the most quintessential, primal, and foundational element of reality.
Magicians use access magic in different ways. Witches and wizards access the High Magic by simply doing magic. Some part of them reaches out and touches that elemental force and some aspect of reality changes. This is miraculous.
But what we haven't discussed yet regarding the nature of magic is that magic can be - and often is - represented as something most people understand as energy. I'm sure a more learned scholar or more practiced Loremaster could talk about different 'kinds' of magicl energy in more depth, but the basic truth of it is that magical energy always exists around us, and the ability to sense and use that energy in some way is what makes a magician capable of accessing Lore.
Ambient magic is magical energy that exists in an undirected state - it is not actively acting upon the world in any way. Ambient magic is omnipresent, and takes many forms, including magical auras. Places with more Ambient Magic can strengthen spells or magical effects and Ambient Magic can be collected in a place if magic used there often.
While all Loremasters can create Ambient Magic and use Ambient Magic in their effects and their effects are always affected by Ambient Magic, High Wizards can create Ambient Magic, and can use magic more effectively in areas of high Ambient Magic, Ambient Magic does not affect them in any other way - outside of the Magic of Circumstance, of course. (The Magic of Intention & Circumstance.)

Using Ambient Magic

When a Loremaster uses magic, they are using Ambient Magic. That is probably the only 'fact' about Lore that exists. More Loremasters reach outside themselves and use this magical energy to do something via Intent.
This is the most basic explanation of lore.

Sorcery

'Sorcery' is a term that gets bandied about and we often consider is to mean the same thing as 'wizard.' And, to a large extent, it is.
But it also very much isn't.
Sorcerer is the term used to describe a magician - a Loremaster - who can channel and directly effect and direct use Ambient Magic. They can direct it, move it, use it to power spells, rituals, and can simply, via intent, make magic happen.
Sorcery is the term we use to describe the Lore of Magic and all that goes along with it.
Sorcerers are always something else: they are not just a practitioner of the Lore of Magic. They are either another kind of Loremaster or a High Wizard.
(It is very likely that sorcerers also always or almost always have mind magic gift, but - there's not really any proof of that, since I might be the only scholar who thinks mind magic is a different branch of magic.)

Aura

Loremasters have talked for a very long time about how ambient magic works, but the one thing they agree on is that the nature of a person defines how they interact with Lore and with Ambient Magic. Or, rather, it reflects the mental state they need to be in to access and use their magic.
One of the major distinctive differences between Loremasters and witches and wizards is that when using or accessing Lore, a Loremaster will often exhibit a visible aura of magic. This is something that can happen when a magician capable of sorcery or other Lore starts using that magic by instinct, or when they purposefully use or connect to Lore and Ambient Magic.
The color of that aura is distinctive and important, because it reflects the method - the emotion or mental state a Loremaster gets into in order to access their Lore.

Color	Represents
Blue	Knowledge. The closer to pure violet, the more knowledge and reason is their focus.
	Understanding of the nature of magic allowing them to access Lore
	Willpower; they force it to happen by sheer determination
Gold	Disciplined Instinct. Also sometimes associated with purpose.
Silver	Hope
	Anger. Violence and violent intent.
	Death magics. Sacrificial magics with dark intent. Necromancy.
	Healing magics. The brighter the aura, the more powerful the healing.
Brown	Elemental and nature magics always have this color
	Desire. Avarice. Hunger. Want.
	Unknown
	Creation. Artificers usually produce this aura.
	Magics of corruption and desecration. Often tinged with black.

What's known about auras is far less than what we don't know and understand. We do know these are generalities.
Most Loremasters will have more than one color in their aura. Usually two predominant, but it is not unusual for a powerful Sorcerer or a Loremaster who has mastered more than one Lore to have many more.
It is exceedingly rare for a magician to have only one color in their aura. The most common incidence of this is a true Necromancer - one who has delved into every aspect of that Lore, and has become the @Unliving themselves.
It hs come to my attention that mind magic also can make use of ambient magic and has it's own auras, but these mean very different things.

Ley Lines

While muggles have their own concept of ley lines, they are only vaguely correct and have a somewhat disorganized and incorrect understanding of them.
Ironically, muggle fiction often has a greater understanding of ley lines.
Ley lines are, quite simply, lines of ambient magic running through and around the world. They are undisturbed by things such as construction, people, or really - anything. They simply are, and they exist in mapped, known patterns for thousands of years.
New ley lines can be formed, of course, and ley lines can be redirected by a powerful enough sorcerer or group of sorcerers, but the basic truth of them remains static.
Ley lines can be stronger or weaker, based on the amount of ambient magic in them. Some are ancient and are deep rivers of ambient magic. Others are small, just a trickle of ambient magic.
There are some cases where many ley lines intersect, creating a 'nexus' of ambient magical power. These are deep wells of energy and quite powerful, and tend to affect the area around them.
Sometimes, small 'pools' or 'puddles' of ambient magic forms - but these are often transitory and fade over time, or are used up by magicians in the area.
The more magic is used in an area, the more magic is drawn to the area, sometimes causing new ley lines to be created, or new nexus points.