A "use case" can be visualized with a UML diagram. UML is an
approach to describe technical software. You don't need to learn
UML, don't be worried. The use case diagram is the most simplest
diagram you can have. It looks a bit like a mind map. Before you
start, I would recommend you to use some a uml editor. One I
love very much is Violet: It is free of charge, has a beauty
interface and is easy to use. On the other hand it lacks some
top-pro features, but they don't touch you. Use case diagrams
are complete. So, below you see a simple use case diagram made
with Violet (image taken from product homepage): A use case is
basically describing "what one can do with the software". Some
elder people simple "feature" to it. Lets summarize a few use
cases for a calendar software. First, you need to identify the
actors. Actors can be human people or other systems. In our case
we can say "Administrator", "User", "System". The last one is
there for some clean up tasks. The first two are humans. Of
course, a Administrat