What is accessibility?

Accessibility is the word used to describe whether a product (for example, a website, mobile site, digital TV interface or application) can be used by people of all abilities and disabilities.

For instance, a website is accessible if all people, including disabled and elderly people, can use it. At the BBC, we aim to ensure that all of our products are informative and entertaining to use as well as being accessible - this is called usability.

On a website, accessibility depends on how a person's disability affects the way they perceive information on a page and how they navigate within and between pages. Elements that affect accessibility include:

• For people who can't see very well: the colours and the contrast between colours; the size of text; the choice of fonts
• For people who are blind: how a screenreader interprets the elements on a page (for example, alt tags for images, and title tags for links); the inclusion of audio description for video content
• For people who can't hear very well: how any audio content is represented graphically (for example, including subtitles or signing on video content)
• For people who find a keyboard or mouse hard to use: the ease with which someone can navigate to parts of the page (for instance, by tabbing); auto-completion of forms
• For people who find words difficult: the length of sentences and paragraphs; the complexity of the vocabulary; the choice of fonts and size of text; the availability of spelling checkers and word prediction; the opportunity to have text read out loud

At BBC Online, our accessibility policy takes into account these factors wherever possible. We ensure best practice for making web pages through our accessibility standards and guidelines.