Not everything in a wireframe will be self-explanatory. That’s where annotations become vital to the process. When viewers can’t actively interact with your wireframes to figure out how things work, you’ll need to annotate them to explain.^[1]

The goal of annotations is to make it clear exactly why your wireframe uses particular elements and how those elements will work and support the overall user experience. You want your wireframes to be as straightforward and clear as possible for those viewing them.