Audience
Who visits you: countries, cities, devices, browsers and languages. All anonymous and in aggregate.
The Audience section tells you what the people landing on your site are like, always in aggregate figures and without identifying anyone.
Locations
Which countries and cities your visits come from. Useful for knowing where to focus, what language to write in or what time to post.
Devices
How many people come from phone, computer or tablet, with which browser and system. If most visit you from a phone, you already know where your site needs to look perfect.
Languages
What language your audience's browser is in. A clear hint about who you're talking to and whether translating is worth it.
Filter and compare
You can cross any piece of data with the rest (country by device, for example) and compare two periods to see if something changed.