Segments are small patches that the scouts can earn for various activities. Many scouts put the segments on the backs of their "brag vests" (red vest). The segments are usually placed in a circle around the Three Fires Council round patch (can be bought at scout stores). You will find that your son will quickly earn many segments if he is active with his den and pack!
Feel free to take a look at the attached document and see what segments are available! (Some segments may now be a different color or redesigned.)