Web Browsers, IP Addressing
A web browser is a software program that allows a user to locate, access, and display web pages. In common usage, a web browser is usually shortened to “browser.” Browsers are used primarily for displaying and accessing websites on the internet, as well as other content created using languages such as Hypertext Markup Language (HTML) and Extensible Markup Language (XML).
Browsers translate web pages and websites delivered using Hypertext Transfer Protocol (HTTP) into human-readable content. They also have the ability to display other protocols and prefixes, such as secure HTTP (HTTPS), File Transfer Protocol (FTP), email handling (mailto:), and files (file:). In addition, most browsers also support external plug-ins required to display active content, such as in-page video, audio and game content.
A variety of web browsers are available with different features, and are designed to run on different operating systems. Common browsers include Internet Explorer from Microsoft, Firefox from Mozilla, Google Chrome, Safari from Apple, and Opera. All major browsers have mobile versions that are lightweight versions for accessing the web on mobile devices.
Web browsers date back to the late 1980s when an English scientist, Tim Berners-Lee, first developed the ideas that led to the World Wide Web (WWW). This consisted of a series of pages created using the HTML language and joined or linked together with pointers called hyperlinks. Following this was the need for a program that could access and display the HTML pages correctly – the browser.
In 1993, a new browser known as Mosaic was developed, which soon gained widespread usage due to its graphical-interface capability. Marc Andreesen, a member of the Mosaic development team, left in 1994 to develop his own commercial browser based on Mosaic. He called it Netscape Navigator, and it quickly captured over 90 percent of the nascent browser market. It soon faced stiff competition in 1995 from Microsoft’s Internet Explorer, which was freely bundled with Windows 95 (and later versions of Windows). It was pointless to buy Navigator when Internet Explorer was free, and as a result, Navigator (and Netscape) were driven into the ground. But while Mosaic and Netscape are no longer around, the age of the browser was launched and continues to this day, as more and more applications move to the web.
An Internet Protocol address (IP address) is a logical numeric address that is assigned to every single computer, printer, switch, router or any other device that is part of a TCP/IP-based network.
The IP address is the core component on which the networking architecture is built; no network exists without it. An IP address is a logical address that is used to uniquely identify every node in the network. Because IP addresses are logical, they can change. They are similar to addresses in a town or city because the IP address gives the network node an address so that it can communicate with other nodes or networks, just like mail is sent to friends and relatives.
The numerals in an IP address are divided into 2 parts:
- The network part specifies which networks this address belongs to and
- The host part further pinpoints the exact location
An IP address is the most significant and important component in the networking phenomena that binds the World Wide Web together. The IP address is a numeric address assigned to every unique instance that is connected to any computer communication network using the TCP/IP communication protocols.
Network nodes are assigned IP addresses by the Dynamic Host Configuration Protocol server as soon as the nodes connect to a network. DHCP assigns IP addresses using a pool of available addresses which are part of the whole addressing scheme. Though DHCP only provides addresses that are not static, many machines reserve static IP addresses that are assigned to that entity forever and cannot be used again.
IP addresses falls into two types:
- Classfull IP addressing is a legacy scheme which divides the whole IP address pools into 5 distinct classes—A, B, C, D and E.
- Classless IP addressing has an arbitrary length of the prefixes.