In Advanced Warfare, you don't build bases. You fight for them. You have to capture control nodes spread over the map.
In order to gain control over for example, a defense line, you have to captures its control node (CN). If the enemy already is ocupying it, you have to destroy the control vehicle that controls said node, it's pretty straight forward: Just shoot at it. After that, you have to put your own CV into the node.
Once you have captured the node, you have control over the defenses there. But watch out, the enemy will probably not be so keen about you having those defenses, expect retaliation. You might want to know that defenses don't have a 360 degree coverage, assaulting them from behind might be a good idea.
There are four types of structures, or "Factories":
-Defensive: MG sites, anti tank guns, shield generators...
-Industry: War factories, air fields, barracks...
-Support: Support airfields, sensor towers and the like.
and lastly, strategic sites, such as Geothermal drills, supply depots, tactical weapons...
Geothermal drills, fusion reactors and the like generate power, needed to power defenses and shields. Supply depots and similar structures generate credits, destroying enemy units also generates income however.
There are two ways to win: Control ALL nodes for 1 minute, or destroy the enemy command hub. To do that however, you have to drop the enemy main shield first, by capturing power relays. If you hold all relay nodes for a certain amount of time, the enemy base's shield drops.