No fixed Center pieces: There are no fixed center pieces in the 4x4 cube, meaning these center pieces can move around the cube, and replace places with each other (unlike the 3x3 where yellow will always remain opposite to white, for example). That means we cannot determine the cube color-scheme by looking at the center pieces (we'll use memory, or corner pieces). As mentioned, there are 4 center pieces for each color. For 4 center pieces solved together we call a center block. (In the image: example of a solved red center block)
Multiple edge pieces: every edge piece in the 4x4 cube has an identical edge piece around the cube, meaning there are 2 edge pieces of every type (e.g. 2 yellow-red edge pieces). In the 2nd step we are going to pair them up together. For 2 identical edge pieces paired-up together we call an edge block. (In the image: example of a paired red-blue edge block)
Sixty-four LEDs makes up this 4x4x4 cube, controlled by an Atmel Atmega16 microcontroller. Each LED can be addressedindividually in the software, enabling it to display amazing 3D animations!
I kept the instructions short for this part, as it's an intuitive part. Just take some time to practice the movements of the 4x4 cube, and you will shortly master the ability to create center blocks intuitively.