If you’re anything like me and can’t find a legitimate reason to purchase Visio but still want to make professional-looking diagrams, draw.io has you covered. It includes options to save directly to a couple different commonly-used platforms (i.e. Google Drive and OneDrive), and also contains most if not all of the shapes you’ll need to get your point across. The closest I can compare it to a commercial product would be Visio 2010 in terms of graphics and variety, but there are also some pretty cool modern-looking 3D shapes. There are many templates you can use to get you started, you can import existing charts from many other programs, or you can just start plugging away on your own.