Just to clear up the slight misunderstanding.
At first the German airforce was bombing strictly military targets in England, in order to soften it for invasion. However, one night. a single German pilot became lost and accidentally dropped his bombs over central London, prompting a retaliation by the British airforce, during which they bombed Berlin for the first time during the war. This so outraged Hitler that he ordered all strikes on military targets, such as the RAF, to be stopped and ordered a merciless concentrated bombing attack on London itself, now known as "The Blitz". Before this started leaders of the RAF had estimated that they could only hold out maybe a couple more weeks, before loosing so many aircraft, so much equipment and personal that they'd become completely ineffective as a fighting force. This break allowed the RAF to rebuild and resupply their airfields, repair their equipment and planes, and allowed the pilots and ground crews a respite from constant bombing. So yes, it was a rather dramatic turning point in the Battle of Britain.