With the exception of some lower-priced models, most digital cameras do have a zoom function. This means you can modify the way a camera sees by 'zooming' from wideangle, to normal, to telephoto. Optical zoom refers to what the lens actually 'sees' and is similar to the zoom on a camcorder, where you press a button and the camera hones in on what you want. Digital zoom actually centers in on a section of an image already taken, and displays in a lower resolution. Most digital cameras have viewfinders that you look through to frame a picture just like standard cameras.
More digital cameras have an added viewing feature which is the LCD screen.
This can be a small screen that's usually attached to your camera that often displays in color. You may use it to pre-view an image or to view a picture almost immediately after it's taken. If you don't like it, no problem, just take another one. You can also see all the pictures you've taken before by scrolling back and fourth. The LCD is certainly a practical feature, but it also consumes a significant amount of battery power.