JSFiddle features a set of four panels, which can also be displayed as tabs in the tabbed layout; three of these panels are designated for code input while the fourth showcases the output: the first is for HTML, where you don't need to include the body, doctype, or head since those are automatically generated, the second is for CSS where styles can be defined, and the third is for JavaScript to encapsulate behavior, with the option to use pre-processors like SCSS. After you input your code, simply click on "Run" in the top actions menu to see the results appear in the fourth panel. Additionally, JSFiddle permits you to modify the editor's layout from the traditional 2x2 grid format to one that better meets your preferences, including the option for a tabbed interface, and the grids themselves are fully adjustable. Notably, when you resize the Results panel, it conveniently displays its width, which is particularly useful for working on responsive designs and media queries. This flexibility enhances the user experience, allowing developers to tailor their workspace according to their specific coding and debugging needs.