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Training · Lesson 1

What is accessibility, and how do I start?

Accessibility means people with disabilities can use something as fully as everyone else. On a website, in a document or in an app, it means a person who is blind, deaf, has low vision, cannot use a mouse, or thinks and reads differently can still find the information, understand it and act on it.

Video coming soon. The full lesson is written out below.

It matters because, for millions of people, the internet is the bridge to the world around them.

Who it serves

More than 1 in 4 adults in the United States has a disability. That is over 70 million people. (Source: Centers for Disease Control and Prevention (CDC), 2022 data, published July 2024.)

Some examples:

  • A person who is blind uses a screen reader, a program that reads the screen out loud.
  • A person who is deaf reads captions instead of hearing a video.
  • A person with low vision makes text very large and needs strong contrast.
  • A person who cannot use a mouse moves through a page with a keyboard or a switch.
  • A person with a learning or memory disability needs plain words and a clear, steady layout.

Many people have more than one need. Many needs come with age.

The bridge

Think about what you do online in a single week. Pay a bill. Read a letter from the doctor. Apply for a job. Sign up for benefits. Read the news. Talk to family.

For a person who is blind or deaf, the internet can make all of this possible without help from anyone else. But only if the page lets them in.

  • A picture with no description is silent to a screen reader.
  • A video with no captions is empty to a person who is deaf.
  • A button that only works with a mouse is a locked door.

When the page is built right, the bridge holds. When it is not, the person is cut off from the same world everyone else uses every day.

That is the real reason for accessibility. The law requires it, and it should. But the law exists because people were being left out.

Who is responsible

If you make, buy or approve websites, documents, forms, videos or apps for the public, part of this bridge is yours. That includes people who:

  • write web pages, letters, forms or reports
  • post videos or social media
  • buy software for an organization
  • manage a website or a team that builds one

You do not need to be a programmer. Most of accessibility is careful, everyday work: clear words, real headings, picture descriptions, captions, and checking that things work with a keyboard.

It helps everyone

  • Captions help in a noisy room or a quiet library.
  • Clear writing helps people reading in a second language.
  • Strong contrast helps on a phone in bright sun.
  • Keyboard shortcuts help people who work fast.

How do I start?

  1. Learn the four plain ideas. People must be able to take it in, work it, understand it, and use it with their own tools. (Next lesson.)
  2. Fix what you control this week. Real headings, picture descriptions, captions, clear link words, strong contrast.
  3. Check with a keyboard. Put the mouse away. Can you reach and use everything with Tab and Enter?
  4. Ask for help where you need it. Bigger sites, many documents and formal reports often need tools and trained people.

Where you fit:

  • "I need to make my organization accessible." Start with the free lessons, in order.
  • "I'm a larger organization or a government agency." Same lessons, plus who owns what, and how to report it.
  • "I want to offer accessibility services." Learn it first, then how to do the work well for others.

In one sentence

Accessibility is making sure nobody is left on the other side of the screen.

Sources (checked 2026-11-01)