Does data flows over Public Internet

Hi All,

I am new to Power BI and working on its pilot implementation in my organisation. However, there are a few architectural questions that have slowed my progress.

Scenario

1. My data source is an on-premise tabular model (SSAS)
2. Gateway is installed and configured properly
3. I have created a few reports using Power BI Desktop. Data source for these is an on-premise tabular model, I mentioned above in 1.
4. I have got 10 Power BI Pro License

 Questions

1. When a user wants to access a report hosted on the Power BI cloud does the report gets downloaded into my organisation's network and then runs? If not does it stays in the Power BI cloud and runs from the cloud itself?

1. If the report runs on the Power BI cloud, does my organisation data moves over Public internet?

1. If the data runs over Public Internet, then does it mean that I have to increase my organisation's public internet handling capacity? How secure is the Azure channel in handling data over public internet?

I will appreciate if anyone with in the community can answer them.

Thanks