3. Internet/ WWW

In lecture 3, we learnt that "the Internet is an infrastructure, and the world wide web is a service that works on that infrastructure [5]". After the lecture, I got experience of the technologies involved by setting up my own website on my home page at City.

Firstly I created a document marked up in HTML (Hypertext Mark-up Language). We learnt in our lecture notes that HTML allows you to link documents on the WWW using hyperlinks; also HTML documents contain both content and mark-up (in the form of tags) and that mark-up allows a browser to interpret your web page's structure and formatting (as well as the meaning of some of its data)[6].

When creating my web page, I used a template provided by the lecturers[7] (templates are also available from sources like Coffee Cup[8]), and typed in some details about myself within appropriate tags, e.g. "<p>" and "</p>" tags to indicate the start and end of a paragraph respectively. I also inserted links to other websites - these were created within a set of tags so that other computers read these as hyperlinks.

I subsequently created an index page and additional page (also in HTML). I linked my index page to the other two pages that I had created - as these pages were not on a web server yet, I created a relative link to the local files.

So far these documents were only on the hard drive of the lab computer, and visible only to me - I needed to make them available on the WWW if I wanted anyone else to see them! I did this by moving my HTML files to a public (W) drive on City's Unix system, running Telnet to connect to Unix, then typing a command to publish my pages.

2. Digital Representation, text/html

In our lecture, we learnt that computers process, store and transmit data by way of binary numbers (0 and 1), with each sequence of numbers being known as a byte[3]. We also learnt that sequences of bytes form files, and files can be created in many different formats - these formats are indicated by file extensions[3] (e.g. .doc. for a Word document).

Our lab work demonstrated different format types: we created a Notepad document, saved it as a Word document, then created an HTML document incorporating a picture (a .jpg).

Our work illustrated that data is represented in different ways, depending on what it is for and what technology you have access to.

As mentioned above, computer data is in the form of binary numbers. We learnt from our lecture notes that encoding, such as the American Standard Code for Information Interchange (ASCII), "can be used to translate between....binary sequences and alphanumeric characters [4]". The result is plain text with no formatting, e.g. Notepad.

If we want stylistic formatting, we can create a document in Word. However Word belongs to Microsoft, and we saw in the lab that you cannot read Word documents if you open them in other applications.

Conversely, we saw that if you save the document in HTML format, you can view it in several different applications. Also, by opening an HTML document in Notepad, you can see it contains "mark-up"; we learnt from our notes that mark-up allows us to add metadata to a document in order to specify formatting and semantic information[3].

The reason for different data representations is that they have different qualities and so are useful for different purposes (e.g. HTML is used to create websites, whereas Word is good for typing up documents). The format used also depends on what you have access to and on your level of IT expertise!