The next few days will be somewhat technical: we'll talk about SERVERs, PATHNAMES, and URLs. Continue working on your homepage: pretty soon, you'll be making it available to the world!
When you "surf the web," there's a computer, behind the scenes, "serving up" your requests. This computer is referred to as the SERVER. When you request a particular document (say, by clicking on a hyperlink), your browser asks your SERVER to get it for you. When you want to make your own HTML documents available to the world, you must "upload" them; it's the SERVER's job to do this, too. Today's lesson gives a brief introduction to SERVERs.
INDEX CARD #16:
SERVERS and more (16a)
"Hardware" refers to the physical storage devices and display devices, like disks, monitors, keyboards, and printers.
You can actually touch hardware, but you can't touch software.
The distinction between software and hardware is sometimes confusing because they are so closely related. When you purchase a program at a store, you are buying software. But to buy the software, you need to buy the disk (hardware).
What are SERVERs and CLIENTs? A SERVER is a (remote) computer running software that enables it to manage resources (like retrieving and storing files). A "CLIENT" is a program (on your own computer) that requests and displays the documents from the server. (A browser is a typical client.) A SERVER usually has many CLIENTs. Web browsers and servers communicate via the HyperText Transfer Protocol (HTTP).
What is a "protocol"? A protocol is an agreed-upon format for transmitting data between two devices.
UPLOADING DOCUMENTS and more (16b)
What is UNIX? UNIX (pronounced "you-nix") is a popular multi-user, multi-tasking operating system developed at Bell Labs in the early 1970s. The majority of web servers run on the UNIX platform. Some popular servers include the NCSA Server, Apache, CERN, Netscape Servers, and Internet Information Servers (IIS).
What do "UPLOAD" and "DOWNLOAD" mean? To "upload" means to copy a file from your own computer to another computer. To "download" means to copy a file from another computer to your own computer.
What is one of the most common transactions that you'll have with your web server? ...the uploading of HTML documents, graphics, and other media files (movies, audio, etc.). Files are transferred between computers using File Transfer Protocol (FTP). You'll probably need an account to be able to upload files to the server; when you set up an account, you'll get an account name and a password. (More on uploading files in a future lesson.)
Printable version of Index Card 16a
Printable version of Index Card 16b