I just started to learn photography. What is focusing, what is focusing and what is composition?

1, focusing is the action process of adjusting the camera lens to make the image to be shot clear or blurred. 2. Focusing is to adjust the lens of the camera. When the photographed image is the clearest, it is focusing. 3. Composition is the expression of the relationship between objects in the shooting picture, such as symmetry, triangle, three points, contrast and so on. 4. "As long as the shutter button remains half pressed, the focal length will be locked. Then you can compose music again as needed. There are two steps in the whole process of shutter. The first step is focusing and focusing the lens, and the second step is releasing the shutter. Take the center point as an example: A aims the center point at the subject, and B gently presses the shutter, but don't press it to the bottom, that is, it is in focus at this time. If it is in focus (the subject is clear, and the camera will have audio/optical prompts), C continue to press and the shutter can be released. If the lens is out of focus, the shutter cannot be released (unless the lens is in manual focus mode). If you want to arrange the subject in the middle of the picture, repeat A and B above, gently move the camera so that the subject is in the position you want, and C, get a picture with the subject not in the middle. Such a picture will not appear rigid. If the camera can directly position the focused object on the screen, the above process is not needed, and the camera can directly focus, focus and release. But this requires the camera to have many focal points to choose from.