While the Power BI suite of business analytics tools is a relatively new product, it incorporates essential components from the Microsoft BI stack. These components are present on both the Desktop and the on-line implementations of Power BI. This is why you can publish a desktop application on-line or download an on-line service and work on it on the desktop. Effectively this means that the desktop can be your development environment for prototyping and trying out ideas. Even at the desktop level you can share Power BI by sharing the .pbix file that stores your data, queries and reports
The first thing to remember about the Power BI desktop application is that it is free! The next thing to remember is that it is a powerful and complex application, and you will need to put some thought into how you are going to use it. You don't need to be a Power BI expert to reap the benefits, once it has been set up, reports are easy to use, and dashboards are easy to create on-line.
There is plenty of help available on-line, and our business is set up to help BI users of all levels of expertise. We have a You Tube Channel that demonstrates some aspects of Power BI. The other aspect of Power BI is that it is highly compatible with Excel and users of Excel Pro and Power Query and Power Pivot will find many of these features available in Power BI