Types of malicious code

• Viruses: pieces of code that attach to host programs and propagate when an infected program executes

• Worms: particular to networked computers, carry out pre-programmed attacks to jump across the network

கண னிமுறைமை (The Computer System)

கண னிமுறைமை (The Computer System)

கணனியென்பது தனியொரு உபகரணமல்ல. மாறாக பல பாகங்களையும் துணை கருவிகளையும் இணைத்து இயங்கும் ஒரு தொகுதியாகும். சில கணனிகள் பார்வைக்கு தனியொரு கருவியாகத் தென்பட்டாலும் பல்வேறு வேலைகளைச் செய்வதற்கு அதனுள்ளேயும் வெளியேயும் பல பகுதிகள் இணைக்கப்பட்டுள்ளன. அவற்றை பின்வருமாறு வகைப்படுத்தலாம்,

Operating System

Objectives of Operating System

• To make a computer system convenient to use in an efficient manner
• To hide the details of the hardware resources from the users
• To provide users a convenient interface to use the computer system
• To act as an intermediary between the hardware and its users and making it easier for the users to access and use other resources
• To manage the resources of a computer system
• To keep track of who is using which resource, granting resource requests, according for resource using and mediating conflicting requests from different programs and users
• To provide efficient and fair sharing of resources among users and programs

Intranet

Intranet

• Intranet is system in which multiple PCs are connected to each other.
• PCs in intranet are not available to the world outside the intranet.
• Usually each company or organization has their own Intranet network and members/employees of that company can access the computers in their intranet.
• Each computer in Intranet is also identified by an IP Address which is unique among the computers in that Intranet.

Computer Network

What is a Computer Network?

A computer network is a system in which multiple computers are connected to each other to share information and resources.

Port

What is a Port?

A port:

• is a physical docking point using which an external device can be connected to the computer.
• can also be programmatic docking point through which information flows from a program to computer or over the internet.

Characteristics

A port has the following characteristics:

• External devices are connected to a computer using cables and ports.
• Ports are slots on the motherboard into which a cable of external device is plugged in.
• Examples of external devices attached via ports are mouse, keyboard, monitor, microphone, speakers etc.