A hurricane is what we call a warm-core system and forms in the warm tropical waters near the equator. It feeds off the warm water. That's why, when they make landfall or move too far north, they weaken - they have lost their fuel. Also, hurricanes are summertime events.
Nor'easters (so named because of the prolonged north-east winds an area receives) are cold-core systems and are formed by a strong area of low pressure that forms off the east coast.
Both storms can be dangerous and cause serious flooding and beach erosion. Some of the worst damage form storms in Hampton Roads has been from Nor'easters, such as The Ash Wednesday storm, March 13, 1962.