How does SLR starry photography shoot stars in the dark?

Prepare a tripod to fix the SLR camera, then set the exposure time of the SLR camera.

When taking pictures at night, due to the dim light, the lens needs long exposure to shoot the starry sky.

But in the process of exposure, the camera should be stable, so a tripod must be used. ...

According to the lens of a SLR camera, it usually lasts about 20 seconds.

And when shooting stars, be sure that there are no other obvious light sources around, otherwise the stars will be easily blocked by other light sources.