Blizzard separates the various battlegrounds into three separate types:[1]

Resource Race
Keep the resources flowing into the stores of your faction by capturing and holding nodes. Stall the enemy, disrupt their operations and you may soon be cruisin’ the road to victory.
Capture the Flag
Sneak into the enemy’s fort, take their symbol of pride (flag) and return triumphantly (means: alive) to your own flag. Do not allow the enemy to take your flag or you will be unable to capture theirs.
Warfare
Ride into the fields of battle and clash with the enemy force. Burn down their towers, obliterate their defences and eliminate, or secure, high priority targets.

Battleground - WoWWiki - Wikia