Power BI is available in different formats:
Power BI desktop: You can download and install PowerBI Desktop on your personal computer where you can connect to the data source, transform your data, analyze and visualize it with templates.
Power BI services: It is a cloud based service or SaaS (software as a service). You can connect to data here as well but the modeling is limited.
Power BI mobile app: One can securely access dashboards and reports on any device with the PowerBI app which is available for iOs, Android and even Windows.
