Territory warfare wiki page.
You are the defending faction. While you have more people on the wall than the other guys, the points ticker counts downwards.
While they have more people on the wall than you do, the points ticker counts upwards.
If the points ticker reaches its maximum value, the attackers win the wall and the associated territory.
If the timer reaches zero without the points ticker reaching its maximum, you as the defender win the wall and keep the territory.
Your faction is way stronger than the other guys, so there's basically 0 chance you lose the wall.
Your faction leadership should be telling you how this works, not me. If they haven't sent you a mail telling you what to do, something's gone wrong. If they have and you haven't read it, go read your mails, silly.