The purpose of this chapter is to introduce the principle of machine addressing. The chapter describes how computers are addressed using a numbering system, how that numbering system is made easier for us to understand using a hierarchical naming system and how several users on one machine can be addressed. This chapter sets out to describe the sorts of ways that information is distributed across the Internet. There are many different forms of communication and information sharing available, each with their own strengths and weaknesses. However, the text-based services still have some advantages, and will be with us for some time yet, for three reasons.
Some Internet users have only text-based terminals available.
Text-based systems have a lower bandwidth requirement, and when users must pay by the volume of data moved text interfaces will be much cheaper. Over slow links, text interfaces, with the much lower amount of data to be transmitted, are much more efficient. Of course, text based systems require more effort to master, and cannot give access to information in graphical form. The software used to implement these services differs markedly from machine to machine. For example, a Macintosh program will, if it is any good, make full use of the special features of the Macintosh user interface.