There are (roughly) two basic types of magic: Innate powers, such as those exhibited by a werewolf or "savant" mage. And ritual magic - magical formulae that can, at least in theory, be practiced by literally anyone.
Innate powers tend to be at least somewhat hereditary; these (aside from occasional special cases such as vampires) represent powers you were born with. The scope, limitations, and strength of an innate power can vary widely; the weakest powers simply manifest as knacks or affinities or just plain luck - easily explained away or ignored, while the strongest powers (roughly one every two hundred years) can manifest obvious power even while surrounded by nulls.
Many innate powers also come with associated drawbacks; for example, your average werewolf finds silver uncomfortable to touch - often likening it to a mild electric current, or something that's just a bit too hot or too cold to hold onto for long.
Ritual magic, on the other hand, is largely learned - though there are certainly people with a related innate talent. In its most basic state, a ritual is a recipe: Do these things, in this order, and you'll get that result. A typical ritual involves drawing some sort of specific pattern - often using a very particular form of ink, some chanted words and accompanying gestures, and often a set of other physical components placed within the confines of the pattern. Those with a bit of skill at it can cut corners somewhat - typically substituting less expensive components, or using a simplified pattern that takes less time to draw. Those with a lot of skill at it can start with a desired effect and research a usable ritual (assuming access to a library of existing rituals that they can crib bits off of.) And those with an absurd amount of skill - typically people with an innate talent for ritual magic and far too much practice - can flat out invent new rituals.
One common ritual at SU is the ritual of the sleepless night - a ritual that temporarily puts off any need for sleep. It's usually performed with a number two pencil, two sheets of blank paper, and a fully charged nine volt battery. The casting takes about five minutes, and the effects last for about 24 hours. Repeated castings can be chained together, though each further repeat has subsequently less effect - and subsequently more consequence when it finally does wear off. A few students have invented a stronger version that actually removes the need for sleep instead of merely delaying it, but that version is both more expensive, and rather more difficult to successfully cast.
Ritual magic also includes most forms of magic item creation, and, at the higher levels of it, "hanging" spell effects that are cast in advance and then triggered later - usually by a word and a gesture, though other triggers are certainly possible.
Major rituals (with casting times measured in weeks or months) can also do things like grant (or change, or remove) an innate power - though such things must usually be customized to the target of the effect. Another common example is the ritual of the darkened sun: an exacting ritual that, quite simply, blocks out the sun. It requires (among other components) a hundred pounds of gold dust, thirteen perfect diamonds (of exactly the right set of sizes and cuts), a forty-one year old (to the second) white elephant, and seven dedicated casters working non-stop for a year - without breaks for food or rest. Nobody has ever cast it. Nobody is quite sure if it would even work - it's suspected that the mage who wrote it down tweaked the ritual a little to render it non-functional. But the design certainly looks good on paper...