In 4-5 sentences, what were the two fronts of war? What were some key battles of the war early on?

A two-front war occurs, when opposing forces encounter on two geographically separate fronts. The forces of two or more allied parties usually simultaneously engage an opponent in order to increase their chances of success. The opponent consequently encounters severe logistic difficulties as he is forced to divide and disperse his troops, defend an extended front line and is at least partly cut off from access to trade and exterior resources.