what does it mean? how are they different? which is better?
The terms are not unique to any brands of auto because the designs are a few decades old. Independent suspension simply means that each wheel is attached or sprung independently of the other and the axle arrangement is not rigid: neither wheel's movement imposes movement on the other. Wishbone suspension describes how each half of an axle, the part leading to any one wheel, is made to pivot around a point on the frame at least halfway across the vehicle, using a stiff linkage that has the shape of a chicken wishbone. The double end surrounds the wheel bearing at its front and rear, and the single end of the wishbone is hinged to some part of the frame. This pair of overlapping wishbones is one way that an independent suspension is accomplished with good left-to-right rigidity, which produces good control of traction and steering. This rigidity shows itself in that the wishbone linkage limits movement of each wheel to a short up-down arc, and each wheel is prevented from moving forward or back or toward or away from the drive train. The suspension has very little effect on the free movement of each wheel in a vertical direction when flexible response to bumps is desired. The design basics are pretty standard. The dimensions of each maker's suspension system are probably unique. Also the strength of the springs limiting the wheel movement will vary with the maker, and depend upon the weight of the vehicle, the weight distribution, maximum and minimum stretching of those springs, and factors that are very design specific. There are other independent suspension designs besides the double wishbone. Because their are advantages to each design, no one type has replaced the other. How each system is going to feel to passengers or how long they will serve without problems does not boil down to only the suspension type.
What Is Wishbone Suspension