Campaign planing is the feature that enables you to prepare a massive campaign before any actual fighting takes place. If you want to erase a heavily defended enemy base it may not be enough to send a group of tanks. You may want to send several battle-groups at once, resulting in massive force. In a campaign you can utilize groups from land, air and sea. You start the campaign by just giving one "go" signal. The massive attack from all sides at once will prevent your opponent from being able to take defensive measures and your chance of success will increase dramatically.
To give you more control over your campaign it is possible to define "way points". These points will be used by your battle groups to find a route to the main target. In some cases it may be possible to use way points to divert the attention of your opponent. Your opponent has no means to tell whether group movement is part of a larger campaign or just a tactical move with only local impact.
Another feature that you may find useful are "synchronization point" or
"syncpoints" for short. These points are like way points with the added
functionality that you can pause battle groups to wait for other events to
happen.
For example, if you plan a large campaign, using jet-fighters and ships, you
want to make sure that both the fighters and the ships arrive at the desired
time at their target position. This can be accomplished by defining syncpoints
just before the final way point.
In a campaign, several things are important. Of course you should use way points and syncpoints to make sure that your campaign hits the enemy as effectively as possible. However, you must also balance the composition of your battle groups. Furthermore, it is extremely risky to leave your own command post without sufficient protection.