Introduction
This is a glossary for web development.
It covers more than 2,000 important, useful, and historic terms and abbreviations relevant for web (and software) developers.
The glossary acquaints and reunites you with the major standards and concepts of the Web, with HTML, CSS, JavaScript, accessibility, security, performance, code quality, internationalization, localization, editors and tooling and more. It then goes beyond web development, touching computer science, design, typography, usability and user experience, information as well as project management, other disciplines of interest and relevance to the modern developer. It goes beyond, encouraging to stay curious to learn more about the Web and the people creating and using it.
The glossary does not tell a story like other books do, but it still tells a story. It tells a story that is sterile yet messy, it tells a story that only started three decades ago and that is still unfolding, and it tells a story that starts with you. Why you? Because you are at your own stage of web development—and because web development is only unfolding, only so alive, because of people like you, people who take a personal interest in it. When you read the glossary like you would read another book, you may tell. (Yet still, it is a glossary.)
About the Glossary
Many explanations and definitions in this glossary are based on Wikipedia and the MDN Web Docs. It was neither necessary nor desirable to come up with a new and different explanation for every term.
Arrows (“→”) point to the expanded forms of abbreviations, and to the more common synonyms and expressions. Sometimes they take you on a little detour, but only to be transparent about the journey taken (like Personal Home Page → PHP → Hypertext Preprocessor, or HTML 5 → HTML → HyperText Markup Language). This may seem lengthy, but it aims to make meanings, relationships, and sometimes history more clear. An arrow may also point at a term that encompasses the referring term, or at a related concept, and therefore does not necessarily indicate equivalence or identity.
Whenever there is a source of great quality or immediate use, explanations include references to external documentation and software.
Some terms and abbreviations have several meanings. Only the tech-related ones are shown.
Sometimes there is imprecision: Is a home page really a special type of web page, yet a homepage just another word for a website? (Per this book, trying to gauge how “most” people use respective terms, it is.)
Unfortunately, there are going to be inconsistencies, probably errors, and perhaps also controversy. Please help improve the glossary as well as, if applicable, Wikipedia and MDN. Giving back to the communities, work on the book has led to numerous small improvements to both Wikipedia and MDN articles, but it is unlikely that these improvements covered all there was to improve. Thank you for sharing your knowledge and taking the time to contribute as well.
Licenses
The Web Development Glossary is licensed under a CC BY-SA 4.0 (Attribution-ShareAlike 4.0 International) license.
A great number of explanations build on Wikipedia. They are marked “†” and attributed in the Appendix. The original material is licensed under a CC BY-SA 3.0 license.
Some explanations build on the MDN Web Docs. They are marked “‡” and likewise attributed in the Appendix. The original material is licensed under a CC BY-SA 2.5 license.
A handful of explanations build on the HTML Living Standard. They are marked “§”. The original material is licensed under a CC BY 4.0 license.
Disclaimer
Use this glossary at your own risk. Despite all passion and care that went into producing this book, I, Jens Oliver Meiert, assume no liability for errors or omissions in its contents. All information is subject to change and provided “as is,” with no guarantees of completeness, accuracy, or usefulness.
This all being said: Enjoy. Web Development is a great field.
