1. A Basic Introduction to the WWW and HTML How the World Wide Web Works

2. What is the WWW ? It’s a service available through the Internet which allows the transmission and rendering of multimedia documents It uses a special protocol named HTTP (HyperText Transfer Protocol) It uses a set of network addresses named URL (Uniform Resource Locator)

3. What is a protocol ? It is a convention or language which allows the communication between any two computers through a network The main protocol used by Internet is TCP/IP (Transfer Control Protocol/Internet Protocol) There are many other protocols running under TCP/IP. Examples: –SMTP: Simple Mail Transfer Protocol –FTP: File Transfer Protocol

4. Uniform Resource Locator http://www.nlm.nih.gov/visible/sample.htm ProtocolHost DirectoryFile Address format for the WWW:

5. WWW: Client and Server Client Computer which is asking for an archive on the net Server Computer which sends the desired archive I Internet

6. Client software: Netscape, Internet Explorer (browser) Server software: WWW Server HTTP WWW: Client and Server Client Server I Internet

7. WWW: Client and Server Cliente Server www.nlm.nih.gov Server www.nlm.nih.gov I Internet Client software: Netscape, Internet Explorer Server software: WWW Server HTTP http://www.nih.nlm.gov/visible/sample.htm Finding Connecting Retrieving

8. WWW: Client and Server Client Server www.nlm.nih.gov Server www.nlm.nih.gov I Internet Client software: Netscape, Internet Explorer Server software: WWW Server HTTP Http://www.nih.nlm.gov/visible/sample.htm Confirmation Transference Closing sample.htm logo.gif return.gif

9. How the Client Works Client Client software browser Http://www.nih.nlm.gov/visible/sample.htm sample.htm logo.gif return.gif The Visible Human Project National Library of Medicine The Visible Human Project National Library of Medicine Script in HTML Rendering by the browser

10. The Visible Human Project National Library of Medicine Amostras WHO The Visible Human Project National Library of Medicine Amostras WHO What is Hypertext Visible Human: Amostras Nesta página você poderá achar algumas amostras de imagens geradas pelo Projeto “Ser Humano Visível” em três dimensões. Visible Human: Amostras Nesta página você poderá achar algumas amostras de imagens geradas pelo Projeto “Ser Humano Visível” em três dimensões. amostra.htm imagem.htm

11. What is HTML ? It’s a language for the specification of documents (mark-up language) It specifies for the browser what are the elements of a page (text, images, etc.) and where and how they should be rendered A text file.HTM contains embedded mark-up commands and tags, enclosed by The browser interprets these tags and commands and renders the page

12. Elements of HTML Tags for document definition: title, head, body, etc. Tags for text definition: paragraphs, color, size, font, emphasis, etc. Tags for placing images Tags for defining hyperlinks Tags for defining tables, forms, frames, etc.