Aperture and how it affects the DOF(depth of field) or how much is in focus in your photo
The 3 Things that effect how much of your photograph is in FOCUS are:
1.The F Stop or APERTURE of your camera.
2.The Focal Length of your lens( how zoomed in your lens is) e.g. 20 mm/ 50 mm/ 70mm etc.
3.How close you are to the subject( the closer you get the shallower the depth of field gets=more things are blurry, less things are sharp.)
Besides a wide aperture, there are 2 more factors that affect the blur between your subject and background, which is called the depth of field (DOF) in a photograph:
1. the distance between your camera and the subject( get close) 2. the focal length of your lens(the more zoomed in the more blur that will occur)however, unfortunately on cheaper lens the more you zoom the narrower your aperture will get(I'll say it again, get a nifty-fifty!) Watch this video to help you in understanding DOF. Here is another video explaining just the aperture part