computer info

Transmission Media The media which are used to transmit and received data in the communication is called transmission media . There are two types of transmission media in the computer network .They are : a. Guided media The media which has end to end connection that wires in between the device is called guided media. It is also known as bounded media or wire media. Due to point to point connection in between devices.The data transmission rate is very high as compared to unguided media .Eg: twisted pair cable, coaxial cable & optical fiber. Some Guided Media 1. Twisted pair cable a. It is most popular media in communication . b. It consists of a pair of insulated wires twisted together. c. It is cheapest and easily available wire which can carry data a large distance without data lost. Fig. of twisted pair cable d. The twisted of cables help to reduces noise from outside source and cross talk on multi-pair cable. e. It is mostly used in telepho...

Network architecture : It refers to the logical and structure layout of the network that transmission devices software and communications protocols and connectivity both the components.It is a design of a communications network . There are two types of network architecture.They are:- a) Peer to peer architecture b) Clients -server architecture a) Peer to peer architecture : It is a distributed applications architecture that device workload both peers . All the peers are equally privileged . All the peers can act as as server or  a client depending on the types of server or a clients depending on the types of services . It follows store and forward method of data transmission. When the communication is done in between the two computers then the others are free for communication. The design is shows in following in the diagram: Fig. of Communication Process  communication process : Let's us consider computer 'A' wants to transmits data of the comput...

Network topology The term topology is derived from geometric & it literal meaning is "shape" network topology refers to the logical or physical inter connection or link in between number of computers in a network . It determines the inter connection and communication between the number of computers in a network. There are different types of network topology & some of major topology are explained bellow: a. Bus Topology: In this structure bus is a connected  to each side of the bus and a terminator in other side. It follows broad casting technique for data communication in   between  the client to the common bus .The basic structure  is shown in the following diagram . Fig. of  Bus Topology Advantages: It is simple and easier to implement . It is more  flexible  It anyone of the clients goes down then the whole system  is not affected. Disadvantages: The data traffic is hi...

Introduction: computer network is a group of computer systems and other computer devices that are linked together through communication channels to provides communication and sharing through of resources among wide range of user . Computer networking is the process of linking two or more computer devices together for the purpose of data and sharing . The first computer network called ARPANET( Advance resource project Agency Network ) was developed by ARPA in 1960's for US defense army . After decide it was released for public.  Purposes of computer network Facilitate communication through e-mail instant machining , video conferencing . Enable multiple user to share a single hardware devices like ; printer , scanner , etc. Enable file sharing approach the network . Allow for sharing of software or operating programs on remote system. centralizing administration and support . Make information easier to access and maintain along network users. Advantages of co...

  Computer Virus  software A computer is a program or small code of segment. Which is written with a malicious intent. It has the capacity to attach itself to existing programs or file and infect them as well as replicate itself without the user's knowledge or permission. It entire into the compute system from external source like CD, pen drive or e-mail and executes when an infected program is executed. Further , as an infected computer gets in content with an uninfected computer ( e.g. through computer networks). virus may pass on to the uninfected system and destroy the files. Effect of Viruses: Some ill-effect that can be caused by viruses are as follows: • Corrupting the data • Increasing the file size • Formatting the hard disk • Slowing down the system • Manipulating the directory contents • Renaming all files with different names Symptoms of virus Infection: There are many different types of computer viruses . Recognizing the symptoms of virus ca...

Introduction to Computer Software For as long as there has been computer hardware, there has also been computer software. But what is software? Software is just instructions written by a programmer which tells the computer what to do. Programmers are also known as 'software developers', or just plain 'developers'. Nothing much is simple about software. Software programs can have millions of lines of code. If one line doesn't work, the whole program could break! Even the process of starting software goes by many different names in English. Perhaps the most correct technical term is 'execute', as in "the man executed the computer program." Be careful, because the term 'execute' also means (in another context) to put someone to death! Some other common verbs used to start a software program you will hear are 'run', 'launch, and even 'boot' (when the software in question is an operating system). Software normally has ...

Computer Hardware Computer hardware (usually simply called hardware when a computing context is concerned) is the collection of physical elements that constitutes a computer system. Computer hardware is the physical parts or components of a computer, such as the monitor, mouse, keyboard, computer data storage, hard disk drive (HDD), graphic cards, sound cards, memory, motherboard, and so on, all of which are physical objects that are tangible.[1] In contrast, software is instructions that can be stored and run by hardware. Software is any set of machine-readable instructions that directs a computer's processor to perform specific operations. A combination of hardware and software forms a usable computing system Von Neumann A rchitecture The template for all modern computers is the Von Neumann architecture, detailed in a 1945 paper by Hungarian mathematician John von Neumann. This describes a design architecture for an electronic digital computer with subdivisions of a p...