People in Medieval times used "heraldry" or a coat of arms to express themselves and be recognized by others. Think of a mascot of a school or a professional sports team. These are so popular you can recognize your favorite team simply by a picture. The same is true about store or product logos. Often you can see a picture and know the name of the brand, store, or restaurant without any words. A coat of arms was very similar.
In Medieval times, a family had their name, a motto or saying, a crest, helmet, and other symbols on their coat of arms. Everyone's was different - no two were the same. And, no one could copy yours. It might take years for a family to design one. After you decided on your design you "registered" it so it was only yours. Nobody wanted to copy someone else's anyway because they wanted theirs to be unique and special to them. Once you had your design registered, your family made a big deal of showing it off. It was flown outside castles, put on shields, sewn into clothing. It might even be burned into the bread baked for family dinners or a party. It was that special. Rich families all over Europe had their own design and could recognize a group from far away based on their coat of arms.
Below are pictures from long ago and pictures of projects done in my class. Mrs. Rausch will print a design for you so we can make our own coat of arms in class.