GIF Image Format
JPG Image Format
Quality and File Size for GIF and JPG
Bitmap and Vector Graphics
https://helpx.adobe.com/photoshop/using/export-artboards-layers.html provides lots of detail; some key points are discussed below.
File > Export > Quick Export as ...
This is partially based on the first part of the Adobe video - https://helpx.adobe.com/photoshop/how-to/export-image-web.html
File > Export > Quick Export as PNG. PNG is the default.
However you can change the default by File > Export >Export Preferences where you can set the default format for the Quick Export to be PNG, JPG, or GIF.
For PNG, you can choose among three possibilities
For JPG, you can set the quality (a number between 0 and 100, with 100 being the best quality and the largest file size)
You can also set the Quick Export Location, whether Copyright and Contact Information will be included, and whether to convert to the sRGB color space (which is the default).
The Quick Export can be accomplished either by choosing File > Export >Quick Export or by right clicking on the layer that contains the image and choosing the Quick Export option.
An alternative to File > Export >Quick Export as ... is to use File > Export > Save for Web (Legacy). This Save for Web (Legacy) alternative will eventually go away but is still present in Photoshop 2022 Release. This option offers greater choices for the gif, jpg, and png formats than the Quick Export or the File>Export Preferences options. For example, forgif and png-8, one can specify the number of colors (2,4,8,16,32, 64, 128, 256).
Revised: November 30, 2021. Comments to William Pegram, email@example.com