Accessibility: The practice of making websites and digital content usable by people of all abilities and disabilities.

Alternative Text (Alt Text): Descriptive text used to convey the meaning and context of an image for users who cannot see it, typically read by screen readers.

ARIA (Accessible Rich Internet Applications): A set of attributes that make web content and web applications more accessible to people with disabilities, especially dynamic content and advanced user interface controls.

Assistive Technologies: Tools and devices used by individuals with disabilities to interact with digital content, such as screen readers, screen magnifiers, and speech recognition software.

Captions: Text versions of the spoken part of television, movies, videos, or presentations, which make content accessible to individuals who are deaf or hard of hearing.

Cognitive Disabilities: Disabilities that affect how individuals process information, learn, remember, and use language, such as dyslexia and autism.

Color Contrast: The difference in light between text and its background, which affects readability, especially for individuals with visual impairments.

Content: Information and sensory experience to be communicated to the user through digital media, including text, images, sounds, and videos.

Descriptive Links: Links with text that clearly describes the destination or purpose of the link, making navigation easier for all users, especially those using screen readers.

Guidelines: General principles intended to help developers and designers make content accessible.

HTML (Hypertext Markup Language): The standard language used to create and design documents on the World Wide Web, which must be used correctly to ensure accessibility.

Keyboard Accessibility: Ensuring that all functionality of web content is operable through a keyboard interface, which is crucial for users who cannot use a mouse.

Media Alternatives: Text-based alternatives for media content, such as captions for videos and transcripts for audio, making content accessible to users with hearing or visual impairments.

Navigation: The process of finding and moving through content on a website, which should be designed to be simple and intuitive for all users.

Operable: One of the four principles of WCAG, indicating that user interface components and navigation must be operable by users.

Perceivable: One of the four principles of WCAG, stating that information and user interface components must be presented in ways that users can perceive.

Predictable: The design and functionality of a website should be consistent and predictable to help users understand and navigate the site more easily.

Principles: The four foundational concepts of WCAG: Perceivable, Operable, Understandable, and Robust (POUR).

Robust: One of the four principles of WCAG, ensuring that content is robust enough to be interpreted reliably by a wide variety of user agents, including assistive technologies.

Screen Reader: A software application that reads aloud the text displayed on a computer screen, often used by individuals who are blind or have low vision.

Semantic HTML: The use of HTML elements to reinforce the meaning of the information in webpages, aiding accessibility and SEO.

Success Criteria: Specific, testable statements that define how web content can meet the WCAG guidelines under each principle. These criteria are categorized into three levels: A, AA, and AAA.

Text Alternatives: Textual representations of non-text content, such as alt text for images, captions for videos, and transcripts for audio files, which make content accessible to users who rely on assistive technologies.

Transcripts: Text versions of spoken content in audio and video files, providing accessibility for users who are deaf or hard of hearing.

Understandable: One of the four principles of WCAG, requiring that information and the operation of the user interface must be understandable.

Usability: The ease of use and learnability of a website, which impacts the overall user experience, particularly for users with disabilities.

W3C (World Wide Web Consortium): An international community that develops open standards to ensure the long-term growth of the Web, including accessibility standards like WCAG.

WCAG (Web Content Accessibility Guidelines): A set of international standards developed by the World Wide Web Consortium (W3C) to make web content more accessible to people with disabilities.