What is Web Server?

Newbie Introduction to the Web

Right now, you are sitting at a computer and viewing this page in a browser. Either you clicked on the link for this page, or typed in its URL (Uniform Resource Locator).
Time to talk about what happened here.

In either case, you issued the request and some server where the website resided furnished it back to you.

The browser broke the URL into three parts:
1. The protocol ("http")
2. The server name ("VodaHost")
3. The domain name ("www.mywebsiteworkout.com")
3. The file name ("whats-webserver.shtml")

The browser communicated with VodaHost Website Hosting service through your ISP to translate the server name "www.mywebsiteworkout.com" into an IP Address (74.86.128.21), which it uses to connect to the server machine.

Following the HTTP protocol, the browser sent a GET request to the server, asking for the file "http://www.mywebsiteworkout.com/whats-webserver.php."

The server then sent the HTML text for the Web page to the browser. The browser read the HTML tags and formatted the page onto your screen.

Clients and Servers
All of the machines on the Internet can be categorized as two types: servers and clients. Those machines that provide services (like Web servers or FTP servers) to other machines are servers. And the machines that are used to connect to those services are clients. So VodaHost is a server that provides a variety of services to customers or clients.

A server can be a client to another server. In order words, a customer can be a client or server.

Because most people have trouble remembering the strings of numbers that make up IP addresses, and because IP addresses sometimes need to change, all servers on the Internet also have human-readable names, called domain names. For example, www.mywebsiteworkout.com is a permanent, human-readable name. It is easier for most of us to remember www.mywebsiteworkout.com than it is to remember 74.86.128.21.

The name www.mywebsiteworkout.com actually has three parts:
1. The host name ("www")
2. The Second-Level Domain name ("mywebsiteworkout") SLD
3. The Top-Level Domain name ("com") TLD

Domain names within the ".com" domain are managed by the registrar called VeriSign. VeriSign also manages ".net" domain names. Other registrars (like RegistryPro, NeuLevel and Public Interest Registry) manage the other domains (like .pro, .biz and .org). VeriSign creates the top-level domain names and guarantees that all names within a top-level domain are unique. VeriSign also maintains contact information for each site and runs the "whois" database.

Domain Name Server
A set of servers called Domain Name Servers (DNS) maps the human-readable names to the
IP addresses. These servers are simple databases that map names to IP addresses, and they are distributed all over the Internet. Most individual companies, ISPs and universities maintain small name servers to map host names to IP addresses. There are also central name servers that use data supplied by VeriSign to map domain names to IP addresses.

Short for File Transfer Protocol, FTP is the protocol for exchanging files over the Internet. FTP works in the same way as HTTP (Hypertext Transfer Protocol) for transferring Web pages from a server to a user's browser and SMTP for transferring electronic mail across the Internet in that, like these technologies, FTP uses the Internet's TCP/IP protocols to enable data transfer.

FTP is most commonly used to download a file from a server using the Internet or to upload a file to a server (e.g., uploading a Web page file to a server).

So What's HTTP?
Hypertext Transfer Protocol (HTTP) is a communications protocol used to transfer or convey information on the World Wide Web. The client or user agent (browser, spider, bot) makes HTTP request. The responding server or the origin server - which stores or creates resources such as HTML files and images furnishes the request with an answer. In between the user agent and origin server may be several intermediaries, such as proxies, gateways, and tunnels spread out all over the world.

Discussing FTP, you mentioned SMTP. What's that?
Simple Mail Transfer Protocol (SMTP) is the de facto standard for e-mail transmissions across the Internet. SMTP is relatively simple (ha), text-based protocol, in which one or more recipients of a message are specified (and in most cases verified to exist) along with the message text and possibly other encoded objects. The message is then transferred to a remote server using a procedure of queries and responses between the client and server. Either an end-user's email client (that's me and you) - closeted technical name for it is MUA (Mail User Agent), or a relaying server's MTA (Mail Transport Agents) (one more time, ha) can act as an SMTP client.

MySQL is the world's most popular open source database software, with over 100 million copies of its software downloaded or distributed throughout its history. With superior speed, reliability, and ease of use, MySQL has become the preferred choice of corporate IT Managers because it eliminates the major problems associated with downtime, maintenance, administration and support.

MySQL is a key part of LAMP (Linux, Apache, MySQL, PHP / Perl / Python), the fast growing open source enterprise software stack. More and more companies are using LAMP as an alternative to expensive proprietary software stacks because of its lower cost and freedom from lock-in.