Internet and networks
A computer network is a group of computers connected to each other so that they can share information and resources. Internet is “network of networks”. It can also be described as an information highway. It is the largest computer network in the world. The networks are linked to academics, researchers, public authorities and include users of all types of profiles, ie companies, individuals, professionals, children, schools, institutes, etc. One remembers all central authority. Internet networking is not directly connected but interconnected. The ability to graphically access Internet resources on the Web is the main reason for the phenomenal growth of the Internet. It should be noted that WWW is similar to Gopher, but instead of being menu driven, it is hypertext based. Most of the problems encountered on the Web are solved by hypertext, become hypertext generation.
Client and server:
The term client refers to the application involved in a communication that actively initiates contact and the term server refers to the application that passively waits for contact.
Characteristics of the client software:
An application program that performs calculations locally
is needed temporarily for remote access
is invoked directly by a user
only runs for one session
runs locally on the users computer
can access multiple services
does not require special equipment.
Features of the server software:
is automatically invoked at boot time
works on a shared computer
accepts customer requests
requires special hardware and operating systems
can handle multiple clients at the same time.
Host and terminals:
Host:
A host is a main computer that contains all programs, data, and processing elements. He has his own method of connection.
A terminal can connect to the host and may or may not have storage and transfer capabilities.
To connect networked computers, cables, connection cards and software are required.
TCP / IP:
TCP (Transmission Control Protocol) and IP (Internet Protocol) are the two types of protocols. A protocol is defined as a set of standard rules that allow communication between computers. The first Transmission Control Protocol (TCP) is a reliable, connection-oriented protocol that allows the byte stream from the sender to be transmitted to the recipient without error. This is the protocol of the transport layer.
The Internet Layer defines a protocol called IP (Internet Protocol) to specify an official packet format. His job is to deliver IP packets to the destination.
The TCP / IP model has five layers:
Application Transport
Network data link
Physical
Some protocols and networks in the TCP / IP model
WWW: the World Wide Web
WWW is a global hypermedia system. This is the most important feature of the Internet. This is commonly known as the Web and is the main reason for the popularity of the Internet. WWW is an Internet server system that supports specially formatted pages and documents. The document follows HTML links and support for other documents, graphics, audio and videos.
Not all Internet servers are part of the WWW.
Internet and the global Web are redefining the global community. Companies have found a new two-way communication place with customers on the website. Businesses can not only advertise, but they can also provide much more information than customers, students and investors would not usually be able to get easily. WWW is a graphical representation of information on the Internet.
hypertext:
The Web includes client computers and servers capable of handling multimedia documents. Client computers use browser software (such as Internet Explorer or Netscape Navigator) to view documents. WWW uses Hypertext Transfer Protocol (HTTP) as the underlying protocol. HTTP defines how messages are formatted and transmitted. HTTP is a stateless protocol. Orders are executed without worrying about previous orders. HTML is an acronym for Hypertext Markup Language. This is the language used to create www pages. Hypertext objects refer to the text and object related to each other.
