How did the battleship changed war in World War 1?

Answer 1

Battleships fought no decisive actions in WWI.

Actually, battleships had a large impact on naval warfare in WW1, just not the impact everyone expect. The complete lack of major surface actions showed that battleships were simply too expense - they cost too much to be used when there was a chance of them being lost. This recognition was slow to sink in, but, nonetheless, had a major influence on the future of naval warfare post-WW1 (as countries searched for alternatives to building more battleships).

In other uses, the battleship was shown to be fatally exposed to two newly-advanced weapons: the torpedo and naval mine. The Whitehead torpedo (either launched from a small craft or submarine) proved to be a simple and cheap threat to the battleship anywhere - the submarine could effectively threaten a battleship with almost impunity. Similarly, more powerful and advanced mine technology threatened the battleship in its role of shore-bombardment.

Overall, it was the lack of effectiveness of the battleship during WW1 which changed naval warfare.

A quick summary of battleships lost in WW1 shows this lack of its effectiveness:

Lost to combination shore battery and mine during shore bombardment: 2

Lost to submarine torpedo attack: 10

Lost to torpedo boat: 2

Lost to naval mine: 4

Lost to surface ship gunfire: 0

Answer 2

It didn't. Convoys kept moving, armies kept fighting, airplanes continued to dog fight.