If we want the width or height unbounded with the soft-cropped sizes for example, what value do we enter; 0 or 9999?

When I upload images into our Media Library, first of all, they do not need to be cropped. In my opinion, if they need to be cropped for whatever they are used for, do it then – not when they’re uploaded. They should be uploaded at their original size.

Getting back to these generic sizes. When do I know when WP is using one of these vague sizes? How do I know what size to set for them, if I have no idea when or how they are used?

When I insert an image, for example, in a Post or on a Page, it almost never is displayed at it’s original size. Sometimes a small image, maybe 50 by 50 px, is displayed at the full page width. So of course it’s horribly pixelated. Other times, an image which actually should be displayed at the full page width, let’s say 1000 X 500 px, it will be displayed at 100 X 50 px.

So I followed a link to this Documention, but it tells me nothing. Is WP indiscriminately choosing one of these sizes for the image I inserted? Otherwise, when does WP use the “Large” size and when does it use the “Medium” size and etc.

How can I guess what specific size to assign to these generically described sizes?

I wish there were some setting to force WP to use the image at its own size, without changing it. Thanks for listening.