A photographic umbrella (known as a brolly in some places) is exactly what it sounds like, just like the umbrella you would use in the rain except these are designed to bounce, reflect, or soften a light source. There are two basic types of umbrellas, bounce and shoot thru. A bounce umbrella is one that you aim the light into and bounce back towards the subject and a shoot thru umbrella is where the light is aimed at the subject through the umbrella making the umbrella act like a large softbox.