Moving around during a battle can be very advantageous. Sometimes it can be confusing to new players, especially with techniques which seem to offer limitless counterattacks. The system is simple.
Each turn of combat is broken down into 2 actions. An action can be to use an Aptitude, move, talk to others, attack or defend. Attacking or defending always cancels your actions and ends your turn, so you must move or use any Aptitudes first.
This means you can move and then attack, but you can not attack then move - unless a technique allows for this. Techniques overrule most every rule as written.
A wise observer might notice that one can effectively move twice, this is true as well. One could lockpick a door and move through it, or move across the room to a chest and lift it. The options are limitless.
If a foe attacks you during an action and cancels, you may start again once you are free of impediment.