Accessibility is the design of products, services, [...] or environments so as to be usable by people with disabilities. The concept of accessible design and practice of accessible development ensures both "direct access" (i.e. unassisted) and "indirect access" meaning compatibility with a person's assistive technology (computer screen readers, keyboard only access).

As an editor, it is your responsibility to help provide accessible content.

Writing accessible text

See also the following W3C page: Writing for Web Accessibility

Provide informative, unique page titles

The title of a page can - in most cases - be influenced in the page properties. Part of the page title - such as the name of the organization - might be added automatically. Ask your developer about this.

Use headings to convey meaning and structure

Almost all content elements have the ability to provide a heading.

Depending on your user rights you may also be able to influence the level of the heading (Headlines > Type). The choice of the level of the heading should be made in accordance to the semantics of the text and not according to design choices.

The rich text editor (RTE) also offers the ability to create headlines of different levels.

Write meaningful text alternatives for images

In TYPO3 when you are uploading or managing an image file in the module File > Filelist you can provide an alternative text in the metadata of this file.

When you are displaying an image as Image content element you can override the alternative text to fit the context or use the default.