SPDAZ

What is a Computer Network? Computer Network  is a group of computers connected with each other through wires, optical fibres or optical links so that various devices can interact with each other through a network. The aim of the computer network is the sharing of resources among various devices. In the case of computer network technology, there are several types of networks that vary from simple to complex level. Components Of Computer Network: Major components of a computer network are: NIC(National interface card) NIC is a device that helps the computer to communicate with another device. The network interface card contains the hardware addresses, the data-link layer protocol use this address to identify the system on the network so that it transfers the data to the correct destination. There are two types of NIC: wireless NIC and wired NIC. Wireless NIC:  All the modern laptops use the wireless NIC. In Wireless NIC, a connection is made using the antenna that employs the  radio wav

What is Virus in computer?  A virus is a fragment of code embedded in a legitimate program. Virus are self-replicating and are designed to infect other programs. They can wreak havoc in a system by modifying or destroying files causing system crashes and program malfunctions. On reaching the target machine a virus dropper(usually trojan horse) inserts the virus into the system. Various types of virus : File Virus :  This type of virus infects the system by appending itself to the end of a file. It changes the start of a program so that the control jumps to its code. After the execution of its code, the control returns back to the main program. Its execution is not even noticed. It is also called  Parasitic virus  because it leaves no file intact but also leaves the host functional. Boot sector Virus :  It infects the boot sector of the system, executing every time system is booted and before operating system is loaded. It infects other bootable media like floppy disks. These are also k