What are manual zoom and automatic zoom in SLR? What is the difference? Is it manual or automatic?

The zoom lenses of SLR cameras are all manually zoomed, and the difference is not very big.

The zoom lenses of SLR cameras are all manually zoomed, that is, the zoom ring is rotated by hand to select the focal length, so there is no so-called automatic zoom. Focusing can be divided into manual and automatic:

Auto focus, turning the lens focus switch to AF is auto focus. When shooting, as long as you press the shutter half, the camera will focus automatically, which is very convenient and fast. Suitable for the most common occasions.

Manual focusing, that is, turning the lens focus switch to MF, is manual focusing. When shooting, you need to turn the focus ring by hand to focus, which is relatively slow, but it is still useful when autofocus cannot be used (such as SLR, dark environment).