Document delivery services allow people to search on-line databases of journals' tables of contents, as well as order copies of the articles found in a database. The unique name that identifies an Internet site. Domain names always have 2 or more parts, separated by dots. It is very similar to street addresses. A set of rules and relationships for structuring data in a SGML-coded file to insure consistency and therefore reusability.
Electronic mail is the most popular use of the Internet .
Like postal mail, it can be used to communicate through written messages which are sent electronically over the Internet . Through email, people can communicate as easily with someone across the world as with someone in the same building. A unit of storage declared and given a name in an SGML DTD . An entity can be referenced in an SGML file and may be a literal string or an external file in SGML or some other notation. FAQs are documents that list and answer the most common questions on a particular subject.