True precision, in the context of moving servos, means being able to control the timing, position, and speed of the servos being used. This level of precision is vital when building meticulous movements that require multiple movements happening in sync to avoid physical collisions. A great example of this is a hexapod robot: each joint needs to move in time with the other joints in the leg, and each leg needs to move at a precise time during a step in order to avoid colliding with each other or throwing the hexapod off balance.

Moving servos with true precision is a daunting task if you are hard-coding it; imagine setting 60 calls to servo.to() in order to create an animation that you hope takes one second. Or hard-coding each movement with servo.to(), timing it with the exact servo you've placed in the leg of your bot, and everything works...until the servo strips (it inevitably will), and you have to replace it and repeat the entire calibration process.

The animation library in Johnny-Five makes this process much simpler by allowing you to define your movements as segments of a larger design, that design being the animation itself. It does all of the math and works out all of the timings to ensure that your servos are where they need to be when they need to be there.