Answer:
The internal carotid arteries (right and left) are the MAjOR arteries that supply blood to the brain. They're the major arteries that branch off from the common carotid arteries (they branch into internal and external carotids, both supplying oxygenated blood to the neck and head).
Of course, these arteries branch off into smaller ones. They split of into anterior cerebral and middle cerebral arteries and then branch off further until they're arterioles, capillaries - I'm sure you know what comes after. (venules and veins but you don't really want those right now...)