Computer Network Basics - Computer Awareness Questions and Answers

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Computer Networks Notes – Computer Awareness Questions and Answers : The basic computer is an important topic for the upcoming IBPS exam and also pertaining to any other bank exams. Computer Awareness is the important topic which is very useful for who are preparing for bank exams like IBPS SBI and all competitive exams of govt. We provide you with the most important points on the computer notes, which are mainly useful for the exam. Glance at the information provided and even be the successful aspirants of the exam. A computer network is a set of devices, which communicate and share resources. These devices are mostly computers, and sometimes stand-alone hard disks, telephone, printers and terminals.

Computer networks are mainly divided into three categories:

Local area network [LAN] – the network of computers in the same building or belonging to the same owner. Inside the LAN every computer is well identified and usually every user is known. It is considered a trusted area.
Wide area network[WAN] – computers which connects the LANs, computers and users identification is very hard. It is considered a dangerous area.
Virtual private network – is a way to recognise a computer outside the LAN as a trusted computer : the user is identified with a password and his computer. VPN is typically required to identify portable computers connected via wireless connection.

Network Components

Hub – Computers are divided into groups and are connected directly to a special device called hub. Every hub is connected to a main hub; in very large companies there are many main hub connected to a higher level hub and so on.
Cables – The network connecting components are the cable, which often determines the speed of the LAN. Cables have a speed measure in bps.(bits per second). Some of the cables are:

ü Ethernet: Cables have a speed of 10mbps and thus carry 1.25MB each second.

ü Fast Ethernet: cables have a speed of 100mbps.

ü Giga Ethernet: cables have a speed of 1Gbps.

Gateway – when a LAN is connected to the internet there is one or sometimes more than one, special computer called gateway dedicated to this connection and to keep relations with the outside world.
Firewall: a program in charge of rejecting unwanted incoming connection attempts and sometimes of forbidding unauthorized outgoing connections.
Domain Name Server: a program in charge of dealing with computer addresses.
Web server: a program in charge of publishing web pages. The web server offers the local web pages to users outside, answering to requests coming from external users.
Mail server: in charge of receiving e-mails from the internet and displacing them to the right local user.
Mail reader : A mail reader is a client program to send and retrieve e-mails. It runs directly on the user’s computer and connects to the local mail server. To communicate with the mail server the mail reader uses special languages called protocols:

Post office protocols to retrieve e-mails at port 110.

Simple mail transfer protocol to send emails at port 25.

Internet mail access protocol is the more modern protocol.

Resource sharing :

Resources sharing is what makes computer networks different from a general networks and this is often over looked by the novice user. Resources which can be shared are:

The processor or the memory : computers and terminals may use the computational resources of a more powerful computer.
Hard disks: computers and terminals often access each other hard disks to read data and sometimes may use a special computer as a storage machine.
CD reader or DVD reader: computers may read CD and DVD physically inside the reader of another computer.