To edit Word, Excel, or PowerPoint documents in Teams previously, you had to click on the "Edit" button while viewing the document, and then either edit it in the full Office app, or the Office Online version of the app.
Today, I noticed that the ability to edit Word, Excel and PowerPoint documents directly within Teams has been added, much to my excitement! Note, I have verified that this works for Word, Excel, and PowerPoint file types as of the time of this blog post. However, I am not sure about others. I verified that it does not work for Visio drawings, but if it ever does, that would be freakin' sweet!
Check out my video below going over this simple, but very welcome, change to working with Office files within Teams.