How Can I Edit and Resize Images for Different Website Screen Sizes?

I'm looking for effective ways to edit and resize images so they display properly across different website screen sizes. While working on the visual content for my business website, Watkins Bail Bonds (watkinsbailbonds.com), provide bail bonds services in San Diego, California, I've been exploring how to make images look clear and professional on desktops, tablets, and mobile devices.

I would like to understand how image dimensions, aspect ratios, resolution, and file formats affect image quality and website performance. I'm also interested in learning how to avoid blurry, stretched, or poorly cropped images when adapting them for different screens.

What tools and techniques do you recommend for resizing and optimizing website images while maintaining good visual quality and fast loading times?