A focal point is the part of an image that draws the eye of a viewer to the most important part of the image or the area that you want to highlight. How you do this will make or break the final image. If you don’t know how to create this point then you will not achieve much in your photography.
Sometimes you will have two focal points and there will be competition, but, you can offset this by using size. One of the focal points must be considerably larger which will draw the eye but immediately your focus will move to the smaller focal point. If they are the same size the viewer’s eyes will dart between them. So be very careful when using a double focal point.
Focus is a basic tenet of photography. It's typically given a definition in photobooks, but not fully explained. The standard definitions of focus are: 1) The position at which rays of light from a lens converge to form a clear and sharply defined image on a focal plane.
Focus is nothing more than the degree of sharpness at a certain point. You can focus on different things, or you can change the aperture to get a larger or smaller depth of field. Either present you with a number of creative options that will help you draw attention to the most important parts of your image. Keep the depth of field small for closeups of your friends and large when you’re doing big open landscapes. It’s a simple rule that will give you some great results.
i went to the music room and took some pictures one of these are in focus and one is not the piano is in focus and the bass is out of focus.