Blind people, those with low vision, and people with other disabilities that affect their ability to read a computer display often use different technologies so they can access the information displayed on a webpage. Two commonly used technologies are screen readers and refreshable Braille displays. As discussed above, a screen reader is a computer program that speaks the text that appears on the computer display, beginning in the top-left corner. A refreshable Braille display is an electronic device that translates text into Braille characters that can be read by touch. These assistive technologies read text. They cannot translate images into speech or Braille, even if words appear in the images. For example, these technologies cannot interpret a photograph of a stop sign, even if the word “stop” appears in the image.
The Americans with Disabilities Act (ADA) was developed in 1990 and is meant to ensure that people with disabilities have the same opportunities as anyone else. This means any businesses that serve the public must make sure their building accommodates people with disabilities of various kinds. And now that the internet is so widely used, ADA compliance also applies to websites and even mobile apps. Basically, this means that your website needs to be accessible to people who have disabilities that affect their hearing, vision or physical capacities.

The question of ADA’s exact wording comes down to two issues: 1) whether the ADA applies to a website at all, and 2) if ADA applies only to websites that have a physical connection to goods and services available at a physical store or location, or if it applies to all websites even if they don’t have physical spaces. Courts are split on these issues but one thing is for certain: the tide is moving toward ADA compliance for websites, and the lack of specific legal wording prohibiting web discrimination has not stopped businesses from being sued.
I have a membership website teaching martial arts. It is accessible only to people who pay a monthly membership fee. I recently had a gentleman in Malta ask if I could make more than 850 videos on the site accessible to him (he is visually impaired). That is an impossible task for a one-man business. If I understand this article correctly, my site is not required to be accessible?
So, without a clear set of accessibility regulations to comply with, how can you tell if your website is compliant? The best measure available is the aforementioned WCAG 2.0 Level AA guidelines. WCAG standards have been the guiding accessibility principle in the European Union and other countries since 1999, with the most recent update taking effect in Spring of 2018. While WCAG is a set of recommended actions rather than enforceable legislation, it forms the backbone of many online accessibility laws around the world and offers a strong model for any American organization striving to provide equal access for all users.

Thank you all for your comments.  In my world of space planning and design of commercial facilities of all types , job # 1 is to make sure you can exit a building in case of heavy smoke and fire and make sure that the space is handicapped accessible and that a disabled person can get out of a building in case of fire.  I have never heard of a handicapped accessible website, however the explanation of a website that refers to a physical space makes sense. Alt text to describe something on a website and /or possible audio enhancements also make sense.   That being said I am also very aware of real and let’s call them faux lawsuits and have concerns about opportunistic lawsuits.  They are already happening and to think that could morph into the web is frankly frightening,  

Level AA is a little more significant, and makes sites accessible to people with a wider range of disabilities, including the most common barriers to use. It won't impact the look and feel of the site as much as Level AAA compliance, though it does include guidance on color contrast and error identification. Most businesses should be aiming for Level AA conformity, and it appears to reflect the level of accessibility the DOJ expects. 
I should mention one caveat to all of this. Businesses that are required to comply but don't have the ability to bring their websites into compliance can provide an accessible alternative to provide the same information, goods, and services that they provide online, like a staffed phone line. The trick, however, is that this option has to provide at least equal access, including in terms of hours of operation. And, as we know, the internet is around 24/7, so good luck with that. 
Courts have essentially taken three positions when approached with this issue. Some courts take the position that the ADA applies to all commercial sites because the law was meant to protect disabled individuals from having a more difficult time than able-bodied individuals from doing business. That is why the website Scribd was unable to get a case summarily dismissed and ended up settling.