This shows the relationship between traffic from a specific country (determined by IP) and traffic with a specific browser language.
For example, if a trader shows 90% en-us language but only 10% USA traffic by IP, this may indicate fraud.
For example, if you see “Hits with lng en: 100, IPs from this countries with this lng: 10”, it means 10 hits came from IPs in the US, CA, or GB (according to geolocation), but 100 browsers had their language set to English.
Some discrepancy is normal. For instance, someone in China might use an English Windows installation, or a person from the US might be traveling with their laptop in China.