Mirrorless cameras, also called hybrid cameras, are compact cameras with an interchangeable lens system. This means you photograph with a great variety of light values and focal lengths. The main difference with classic SLR cameras is that mirrorless cameras don't have a mirror. You now find the images thanks to the electronic viewfinder or on the LCD screen instead of the optical viewfinder. This created a lot of space, making the body's and lenses more compact.