I'll add-on to this as I was crafting a similar reply in my head. @dbrace have a pretty good overview of Canvas from a tech perspective. While there are many things Canvas *could* do, it is really meant to be a learning management system (virtual class space).
I'm not sure if the question was being asked from a technical or practical perspective though, so I'll offer another side... If you're using an instance of Canvas that your school/institution pays for, there may be policies/rules/procedures in place around what Canvas can be used for and who exactly can use it as your particular school/institution. The institution I work for has policies like this in place which do allow for Canvas to be used for things other than official courses, but those things still need to be related to learning. For example, if we got a request to create a Canvas course just to hold files, we'd say no as there are other services for that purpose. Similarly, if people just want to have a discussion or communicate, there are other tools for that purpose. It's the need to combine a lot of functionality into one thing focused on learning where Canvas shines. With all that being said, I know some schools are much more open to having non-course Canvas sites than we are, while some are even more restrictive.
I hope this additional info might be helpful too!
-Chris
