Command points limit the maximum number of Sworn Swords you can send on Adventures, Alliance Vs Alliance Actions and/or Player to Player Actions at the same time. There are no limits to the number of sworn swords that can be sent out on Quests, Alliance Challenges, and/or friends' Boss Challenges.
You begin the game with 5 command points, gaining an additional point at level 5 and every 5th level thereafter. You can also boost your command points by investing on the level 90 Fealty Talents.
Command points are shown on the right side of the screen at the top of the Sworn Sword panel, the top left of the Adventure Party interface, and the top right of the Player to Player interface. The format of command points is Points in Use/Total Command Points.
You can calculate your command points dividing your current level by 5, rounding down and adding 5.