The movement of the unit.
This is the number of steps the unit can make in a single round. These steps can be directly to the next tile or diagonal. When the tile of an enemy unit can be reached the unit there can be attacked in the same round.
When a unit has not moved the total movement and has not yet attacked another unit it is possible to wait and attack a unit that comes into close distance of it before the other unit can attack.
Each turn the units can move their normal movement+1 times 3 on the overland map. So a unit with movement 3 can move 4*3=12 tiles in a single turn. The players do their turn one after the other. When an enemy unit is in a tile the four neighbour tiles are controlled by this unit and it is not possible to move through that tiles without attacking that unit.