Rake/Trail is (if I recall and translate correctly) something with your front tire.
Rake is the angle your forks are set (not sure about this though),
Trail is the difference between the center of your wheel above ground and the contact patch of your tire.
Compression Ratio-
When the piston moves up, and the valves are shut, the air/fuel mixture in the cylinder is compressed.
12:1 Means: you have 12x the atmospheric pressure than your surroundings.
Stroke X Bore = Displacement.
Stroke is how much the piston moves up and down, Bore is the width of your cylinder. As you may recall from school, space is area * height.
To calculate the area, you need also the number Pi for bore is only the diameter.