In nutshell it's like add-on ability that help your squad have more adaptability.
Like you want a super fast group to full clear map but don't have enough speedy unit
You can use 移動力UP to increase speed for specific group.

The detail alredy in wikia link unregistered-san post.
You can self-study it, and if you still curious you can come back with more question.
Everyone here will answer as much as we can.