Orientation is an important part in games and getting the terminology down correct helps with pesky computations. So here goes...
Heading is where you are pointing to, relative to North
Course is where you intend to move to, relative to North, which may be affected by external powers (like wind)
Track is the path you've traveled so far
Bearing is where you are moving to and comes in two flavours:
- relative bearing is the angle of your heading to your intended target
- magnetic/true bearing is the angle of North to your indended target