Finger independence is important. It helps with speed, accuracy and control, all very integral to making music.
To work on our finger independence this exercise, called Fixed Fingers, takes three fingers and locks them in place while the remaining finger jumps around, independently of the others. Starting out with 2,3 and 4 fixed down on the 6th 7th and 8th fret, your first finger can play from the first to the sixth string and back again, skipping the third string which has the fixed fingers. Then continue to swap fingers to allow the 2nd finger, 3rd and fourth do the movement.
Once you have nailed that, you can start using two fingers at a time in contrary motion, more difficult but great practice. Especially when you get to the ever stubborn pairing of 3 and 4….