There are two ways to make a background transparent in Photoshop: using the "Remove Background" quick action or manually by using selection tools.

If you attempt to save your Photoshop document as JPEG or JPG but it refused to save, you may need to change the image’s color mode. To change the color mode go to the top menu bar and press Image ...

Most web browsers and photo viewers can open this common image file format A PNG file is a Portable Network Graphics file.

If you work with large Photoshop files, you’re probably well aware of how slowly they save. Much of that time is spent flattening your image in order to create the preview icon you see in the Finder.