Responsive mobile first website

Any problem that you encountered in this solution please tell me so I can improve upon it, any criticism is appreciated

This project raised a bunch of questions I wanted to ask

I was wondering what's the difference between srcset image loading and css background url loading

I read a bunch of articles and videos on this subject but can't seem to find an answer to it

If you have a background url in your mobile and desktop versions, would the website load the mobile image and the desktop image if you were using a computer or a phone?

I know this might seems like a dumb question but I was wondering about it when I first started this challenge and it kind of derailed me into asking this question

is it better if I use html's srcset instead of css's background url?

Again thanks for looking at my solution and thanks for the advice in advance

Take care!