Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Dia is an editor for diagrams, graphs and charts. It is the perfect tool to use for explaining a process or procedure in a concise, standardized visual representation.
You will find numerous diagramming applications in both the commercial realm for Windows PCs and the free open source marketplace. Many of them are very lightweight tools. Others are very complicated and not easy to use well. That is not the case with Dia, however.
Dia gives you a fairly large library of diagram objects. It is easy to learn for new users and has the flexibility power users need to create highly customized diagrams.