Data Formats on the Web

1. Content Negotiation
 - used in HTTP to allow servers to send different representations of the same resource at the same URI
 - The user agent tells the server which encoding, language, media type, etc. it prefers, and the server responds with the "best" representation

https://www.w3.org/Protocols/rfc2616/rfc2616-sec12.html

2. Internet Media Types
 : composed of a type, a subtype, and optional parameters
 e.g. text/html, application/pdf, video/mp4, image/png
 1) Plain Text
  - ASCII: ASCII maps the 1-byte numbers 0-127 into letters
   * 1byte = 8bits = 0 - 255, but the 8th bit was used for error correcting (parity bit)
  - Unicode: uses 4-byte numbers
   * allows 1-byte (8-bit) representation: UTF-8
 2) HTML: structured for main applications of Web pages
  * incorporates stylesheets, media, scripts
 3) XML: more general document and data language than HTML
 4) MathML: facilitates the use and re-use of mathematical and scientific content on the Web
 5) SVG: a language for describing 2D graphics in XML
  * compared in Canvas (Native HTML Drawing)
 6) Office Open XML: a zip file of a directory hierarchy of lots of XML files
  * From Office 200, Microsoft moved to XML-based formats
 7) ePUB: an HTML-based e-book file format with the extension .epub that can be downloaded and read on smartphones, tables, computers, or e-reader devices except Amazon Kindle e-readers
  - Reflowable document for e-readers => Re-sizeable font, and changeable text and background colours
  - file is a zip archive that contains, in effect, a website
 8) PDF: structured for rendering of pre-formatted documents
  - Many business, publishing and records-keeping applications require a reliable, flexible and capable and immutable analog for paper
   => people use when they need an electronic "hard copy"
   => pdf is often used as the final, official format of record

http://idpf.org/epub

https://blogs.adobe.com/documentcloud/top-10-reasons-to-use-pdf-instead-of-word-excel-or-powerpoint/