Web Browser

Week 3.

    Hey hey hey..haha...this week i know better what is telecommunication and networking. And this week we are learning about web browser. A web browser is :

     -software application that enables a user to display and interact with text, images,and other              information typically located on a web page at a website on the World Wide Web or a local area network.

    -software that displays web pages.

    -software that gives users a access to the World Wide Web.

Although browser are  primarily intended to access the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems . The major web browsers are Firefox, Google Chrome, Internet Explorer, Opera, and Safari.

   And below chart show the percentage of people use the web browser in 2011.

   Search Engine

     -enable user to search internet using keywords( software ) 

     - allow user to summit a query that consist of a world phrase.

     -searches the database.
     -returns a lists of suitable ULR.
     -allow user to revise and resumit.

   

Cache

• Cache (computing), a collection of data duplicating original values stored elsewhere on a computer
• CPU cache, a small area of fast memory used by the central processing unit
• Disk buffer, the small amount of buffer memory present on a hard drive
• Page cache, the cache of disk pages kept by the operating systems, stored in unused main memory
• Web cache, a mechanism for the temporary storage of web documents to increase performance
• DNS cache, a server in the domain name system which stores queried results for a period of time
• P2P caching, a technique used to reduce bandwidth costs for content on peer-to-peer networks
• Database caching, a mechanism used to cache database content in multi-tier applications

URL

Abbreviation of Uniform Resource Locator (URL) it is the global address of documen and other resources on the World Wide Web.

The first part of the address is called a protocol identifier and it indicates what protocol to use, and the second part is called a resource name and it specifies the IP address or the domain name where the resource is located. The protocol identifier and the resource name are separated by a colon and two forward slashes.

For example, the two URLs below point to two different files at the domainpcwebopedia.com. The first specifies an executable file  that should be fetched using the FTF protocol; the second specifies a web pages that should be fetched using the HTTP protocol:

ftp://www.pcwebopedia.com/stuff.exe 
http://www.pcwebopedia.com/index.html

A URL is one type of Uniform Resource Identifier (URI); the generic term for all types of names and addresses that refer to objects on the World Wide Web.

The term "Web address" is a synonym for a URL that uses the HTTP / HTTPS protocol.

The Uniform Resource Locator (URL) was developed by Tim Berners-Lee in 1994 and the Internet Engineering Task Force (IETF) URI working group. The URL format is specified in RFC 1738 Uniform Resource Locators (URL).

Multitasking

The ability to execute more than one task at the same time, a task  being a program. The terms multitasking and multiprocessing are often used interchangeably, although it implies that more than one CPU is involved.

In multitasking, only one CPU is involved, but it switches from one program to another so quickly that it gives the appearance of executing all of the programs at the same time.

There are two basic types of multitasking: preemptive and cooperative. In preemptive multitasking, the operating system parcels out CPU time slices to each program. In cooperative multitasking, each program can control the CPU for as long as it needs it. If a program is not using the CPU, however, it can allow another program to use it temporarily. OS/2, Windows 95, Windows NT, the Amiga operating system and UNIX use preemptive multitasking, whereasMicrosoft Windows 3.x and the MultiFinder (for Macintosh computers) use cooperative multitasking.

Plugin

In computing, a plug-in (or plugin) is a set of software components that adds specific abilities to a larger software application. If supported, plug-ins enable customizing the functionality of an application. For example, plug-ins are commonly used in web browsers to play video, scan for viruses, and display new file types. Well-known plug-ins examples include Adobe Flash Player, QuickTime, and Microsoft Silverlight.

[Plug-in (computing)|Add-on]] (or addon) in computing is often considered the general term comprising snap-ins, plug-ins, extensions, and themes for software applications.

Applications support plug-ins for many reasons. Some of the main reasons include:

• to enable third-party developers to create abilities which extend an application
• to support easily adding new features
• to reduce the size of an application
• to separate source code from an application because of incompatible software licenses.

Specific examples of applications and why they use plug-ins:

• Email clients use plug-ins to decrypt and encrypt email (Pretty Good Privacy)
• Graphics software use plug-ins to support file formats and process images (Adobe Photoshop, GIMP)
• Media players use plug-ins to support file formats and apply filters (foobar2000, GStreamer, Quintessential, VST, Winamp, XMMS)
• Microsoft Office uses plug-ins (better known as add-ins) to extend the abilities of its application by adding custom commands and specialized features
• Packet sniffers use plug-ins to decode packet formats (OmniPeek)
• Remote sensing applications use plug-ins to process data from different sensor types (Opticks)
• Smaart, an audio spectrum analysis application which accepts plug-ins for third-party digital signal processors
• Software development environments use plug-ins to support programming languages (Eclipse, jEdit, MonoDevelop)
• Venue, a digital mixing console architecture developed by Digidesign and owned by Avid Technology, allows third party plug-ins
• Web browsers use plug-ins (often implementing the NPAPI specification) to play video and presentation formats