The recommended approach is to use the Media Library. Enable the Media and Media Library core modules, then add a Media reference field to your content type that targets Image media.
When editing content, click the field’s Add media button to open the library, upload new images, or reuse existing ones. This approach keeps images organised and reusable across content.
For inline images within rich text fields, configure the text format to include the Media Library embed button. Editors can then insert images directly into the text. Drupal automatically handles responsive image delivery if you have set up image styles and breakpoints. Avoid the older approach of adding image fields directly to content types unless you have a specific reason. The Media Library is more flexible and provides a better editor experience overall.