That's a very good question. The "Raw Odometer" refers to the odometer value directly reported by the engine, whereas "Odometer" is the addition of the Raw Odometer + any offset that was made by another user. For example:
You can have a vehicle who's engine reports 3400 km but the vehicle's dashboard reports 3550 km. If you wanted the dashboard to match what Geotab shows, you can input an odometer offset of an additional 150 km on the UI to make them match. The Odometer then becomes:
Odometer = Raw Odometer + 150 km
You can make this change by going on the Vehicle Edit page and simply changing the odometer displayed there. So in this case, it would show as 3400 km, and you would change it to 3550 km, which would automatically create an offset of +150 km
That new Odometer will then reflect on the Vehicle Edit page, as well as the IFTA report. As opposed to showing the Raw Odometer values.
If you'd like to fix the odometer discrepencies shown on that picture, please create a Support Ticket with us through Helpdesk, and we can walk you through the steps.