Who won the battle of somme? explain

Neither side really won. The British and French, who started the battle, won some ground, but it wasn't much and their casualty rate was very high. The British & French lost about 620,000 men; the Germans lost about 500,000.

The goal of the battle was to make a breakthrough against the German lines and to take some of the pressure off of French troops who were fighting the Germans at Verdun. I believe the casualties were higher at the Battle of the Somme than at Verdun.