الأربعاء، 14 ديسمبر 2011

A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information
Technically, Network is defined as "If at least one process in one computer is able to send/receive data to/from at least one process residing in a remote computer, then the two computers are said to be in networkNetworks may be classified according to a wide variety of characteristics such as the medium used to transport the data, communications protocol used, scale, topology, and organizational scope.
The rules and data formats for exchanging information in a computer network are defined by communications protocols. Well-known communications protocols are Ethernet, a hardware and Link Layer standard that is ubiquitous in local area networks, and the Internet Protocol Suite, which defines a set of protocols for internetworking, i.e. for data communication between multiple networks, as well as host-to-host data transfer, and application-specific data transmission formats   
Computer networking is sometimes considered a sub-discipline of electrical engineering, telecommunications, computer science, information technology or computer engineering, since it relies upon the theoretical and practical application of these disciplines

internet teaching learning and research

our leacture was very interesting.It was about internet.We learned how to deal with internet.It was very interesting lesson.I like your way in teaching because make the lesson very interesting and out of routain.realy I hope to be like your ways in teaching in the future.U r successful teacher

الأحد، 4 ديسمبر 2011

اجزاء الكمبيوتر

learning/teaching aids

The leacture is very benefit for me .I learn what i will use to be help my student in the future until understant and remember what i teach in the lesson.It is easy , intersting.and interactive.

computer

The lecture was interesting.I enthus to use the computer in my lesson in the future .Also ,i learn new things about ,the blogger.I will practice what i learned

السبت، 3 ديسمبر 2011

Different Types of Computer Viruses

Different Types of Computer Viruses
There are different types of computer viruses which can be classified according to their origin, techniques, types of files they infect, where they hide, the kind of damage they cause, the type of operating system or platform they attack etc. Let us have a look at few of them

Resident Virus
This type of virus is a permanent as it dwells in the RAM. From there it can overcome and interrupt all the operations executed by the system. It can corrupt files and programs that are opened, closed, copied, renamed etc

Examples: Randex, CMJ, Meve, and MrKlunky.

Direct Action Viruses
The main purpose of this virus is to replicate and take action when it is executed. When a specific condition is met, the virus will go into action and infect files in the directory or folder that it is in as well as directories that are specified in the AUTOEXEC.BAT file path. This batch file is always located in the root directory of the hard disk and carries out certain operations when the computer is booted

Examples: Vienna virus.

Overwrite Viruses
Virus of this kind is characterized by the fact that it deletes the information contained in the files that it infects, rendering them partially or totally useless once they have been infected. The only way to clean a file infected by an overwrite virus is to delete the file completely, thus losing the original content.

Examples: Way, Trj.Reboot, Trivial.88.D.

Boot Sector Virus
This type of virus affects the boot sector of a floppy or hard disk. This is a crucial part of a disk, in which information of the disk itself is stored along with a program that makes it possible to boot (start) the computer from the disk. The best way of avoiding boot sector viruses is to ensure that floppy disks are write-protected and never starting your computer with an unknown floppy disk in the disk drive.

Examples: Polyboot.B, AntiEXE.

Macro Virus
Macro viruses infect files that are created using certain applications or programs that contain macros. These mini-programs make it possible to automate series of operations so that they are performed as a single action, thereby saving the user from having to carry them out one by one.
Examples: Relax, Melissa.A, Bablas, O97M/Y2K

انواع الكمبيوترات الحديثة






هواتف عجيبة غريبة







الثلاثاء، 18 أكتوبر 2011