A few years ago I didn’t know what the term “accessibility” meant. I built Web sites that were partially inaccessible because I didn’t know better. Fast forward to today, I know enough to be able to write, speak and run workshops on accessibility, helping others build more a accessible and inclusive Web. Much like everyone else in our field, I am still learning. But since I started, I learned a lot of valuable lessons and core values that drive my work today. Here are a few of them.

Semantic HTML is the foundation of a truly accessible Web.

Semantic HTML is the universal language that all devices accessing the internet understand. It is the language you use to communicate your content to these various devices, including but not limited to browsers, reading apps, screen readers, smart watches, and more.

HTML is semantic, or in other words, it is descriptive and provides meaning — each HTML element describes the type of content it presents. So if you have a heading, you use a heading element. If you have a paragraph, you use a

tag. In other words, it means using the correct HTML elements for their correct purpose.

By using correct elements, your document content will have conveyable structure and meaning.

Structure is important because it helps interoperability. Interoperability is the ability of different systems, devices, applications or products to connect and communicate in a coordinated way, without effort from the end user. In other words, it allows more devices to interpret and access your content, including devices that will show up in the future.

Structure helps applications like reading apps and reader modes (such as Safari’s reader mode) as well as environments like Windows High Contrast Mode understand your content and style it in ways that improve the user experience. This is only possible when the proper HTML semantic elements are used, such as