In PHOTOSHOP, the method to add a copyright watermark to a photo is:

1. Make a copyright watermark.

A copyright watermark is a pattern or text that can reflect the culture of the copyright owner and represent the mark of the copyright owner. It is also called a LOGO, which is called a symbolic pattern or pictogram. Any form of mark is protected by law if it is registered and is called a "trademark".

Watermarks are generally saved in PNG format with a transparent background.

2. The use of watermarks.

In PHOTOSHOP, open the original image, go to File--Insert, insert the watermark image, adjust the size and position, and finally merge the layers