The photographer pointed out the maze. Lens problem.

There are too many questions to tell you one by one.

Does F3.5 -F5.6 written on the first question refer to the maximum aperture of 3.5 and the minimum aperture of 5.6? If yes, why is the aperture F 1 1 when I take a picture? If not. Is aperture related to focal length? If the focal length is too long or too short, the aperture can't reach the maximum value of 3.5.

The answer F3.5 -F5.6 indicates the maximum diameter of DT 18-55 ferrule/3.5 at kloc-0/8 end and 5.6 at 55 end.

When I took pictures, I found that I turned the aperture up by 3.5. Then I turn the lens and the aperture value changes.

That's right. When you turn the focus ring from 18 to 55, the aperture will change between F3.5 and F5.6.

The second question is whether focusing adjusts the focal length of the camera. Make the subject clear?

The second half of what you said is right. The focus ring is used to make the subject clear, and the focal length of the camera is adjusted by the focus ring.

I will focus automatically when the lens is turned to 55 mm. Isn't the focal length of the lens actually at 55 mm?

I know what you mean. If you set the lens to 55 and then focus automatically, the focal length will not change.

I know the focal length of the blurred aperture. The influence of shooting distance. Macro photo of my 18-55 jumper. What's the point of bugs? What is the aperture? How far is it to take a bust? As if I knew this shot was difficult. But I want to be a little vague. How focused are you? What about the aperture?

You have to explore this yourself slowly, and I can't tell you.

But I can give you some experience.

When the aperture value is fixed, the longer the focal length, the more blurred the background.

In the case of fixed focal length, the larger the aperture, the more blurred the background.