A question that many people ask is what is a full frame image sensor and how is it different? The answer is actually very simple. A full frame image sensor if of the same size as a 35mm film frame. Confused? Let me explain with the help of a picture.
Let us say that you took this picture with a full frame camera and then again with another camera with a cropped sensor. There is no change in lens and both the cameras have same lens mounted. If the full frame sensor captured the entire image, a cropped sensor would only be able to capture the area within the square box. Lens choice here
A full frame sensor has several advantages. One that is obvious from the picture above is that it is able to capture a greater area than a cropped sensor. Another advance comes in terms of picture quality which is far better than a cropped sensor. A photographer also gets a greater range in terms of aperture and ISO when shooting with a full frame camera.
The only disadvantage that can be pointed out is that a full frame sensor is larger in size which makes an already bulky DSLR even bulkier and it also costs more money than a cropped sensor.