[M Fifty]

Well, each line of a particular colour represents a damper setting (compression or rebound). The vertical axis is recording the resistance (damping), while the horizontal axis is recording how quickly the damper was being made to compress or extend.

So the rhs side of the horizontal axis is a pothole, bolt down speed bump or really big trackside marker, hit at speed, while the lhs is a fast sweeper of a corner.

Noting that damping is proportional to the velocity, you want a damper that lets the suspension absorb the the potholes etc, while resisting roll in corners.

All of the above do that in compression on the front, some don't do it in compression on the rear, some do it in rebound, some don't (which is not a bad thing - you want the suspension to recover quickly to be ready for the next bump).