Session 2: data and HTML

INM348 - Digital Information Technologies and Architectures

Binary - counting in base two - underpins all of computing. Data exchanged by computers is expressed in binary, which is expressed as a string of zeros and ones. So, for example, the number 56 is 0011010100110110.

We create formats to enable computers to present this data to us as words, numbers and pictures. For example, ASCII (the American Standard Codes for Information Interchange) is a format to translate 7 bit binary codes into words and numbers.

There are other ways to encode binary data to provide us to do more, such a structuring documents with headings and paragraphs, and so on. We can encode this data about the document and its content - the metadata - into the document, to make it more intelligible. And we can use a system of marking the document up, using tagging, to help our computer software present the document in the way we want it. HTML - the markup language used to structure and present documents on the world wide web - uses tags in angle brackets to denote headings and paragraphs, like this:

<h1>Here's an example of a heading tag</h1>

<p>Here's a paragraph tag.</p>

Fig 1. Examples of tags.

This is all pretty fundamental - after all, binary data is arguably essentially meaningless unless it is formatted and interpreted in some way so it can be converted into information and knowledge.

In this session, we also looked at the differences between a file-centred and document-centred view of managing data. Networked environments enable us to adopt a the latter view, in which a document can comprise of a disparate set of files – graphics, text, video and so on – which are stored in diverse locations, and linked with special tags. This enables us to make our web pages more interesting, but also manage them more efficiently; so rather than embedding large files, we simply link to them.

Word count for this entry, excluding figures and captions: 297 words.