Differentiate between system software and application software

Q. Differentiate between system software and application software

System Software:

System software is a set of programs to control all components of computer and to manage overall operations of computer system. System software is used as a base to install and run all application software. Examples of system software include:

1. Operating Systems, like Microsoft Windows, DOS, Unix and Linux
2. Device Drivers like Device driver software of a Printer (found on CD normally provided with the printer)
3. Utility Programs like AVAST anti virus, Disk Scanners and File Viewers etc.

Application Software:

Users can use Application Software to perform different applications on computer. Application Software generally performs a specific task for a computer user. Examples of Application software include:

1. Word processors like Microsoft Word
2. Spreadsheet Software like MS Excel
3. Database software like Microsoft Access etc.

Difference between System & Application Software

System Software	Application Software
1. It is a set of programs to control computer components and operations.	1. It is used to solve particular problems of user.
2.  It is general-purpose software.	2. It is specific purpose software.
3. It executes all the time in computer. Because it controls overall operations and components of computer.	3. It executes as and when required. For example, if we need to write a letter, we will open Microsoft Word - an application software. And after we have written and printed the letter, we will close Microsoft Word.
4. The number of system software is less than application software.	4. The number of application software is much more than system software.
5. System software is essential for a computer to work. Without System software (like operating systems), a computer is useless. We cannot use computer hardware without system software. That is why we install an operating system first of all, after buying a new computer.	5. Application software is not essential for a computer to work. For example, if we need to play some games then we buy a game CD or download games from internet, and install in our computer.
6. Examples are: Windows, Dos, Unix, Linux, Norton Antivirus etc.	6. Examples are: MS Word, MS Excel, MS Power point etc.

 

Differences between LAN and WAN

The differences between LAN and WAN is as follows:

LAN (Local Area Network)
1.	LAN is used to connect computers at one place, in one room or a building.
2.	LAN covers small and limited area.
3.	Data transfer speed is very fast in LAN because of small distance.
4.	Local Area network speed is normally form 1 to l00 Mbps.
5.	LAN is less costly.
6.	LAN is usually connected through wires.
7.	Normally, the   connection    in    a    LAN    is permanent using wires.
8.	LAN is used for sharing data, information, files and hardware like printers, hard disk, modem etc.
9.	LAN has   less   possibility   of data transmission error.
10.	LAN is used to transfer data over small distances.
11	LAN is easy to install and configure.
12	LAN is easy to troubleshoot.
WAN (Wide Area Network)
1	WAN is used to connect computers anywhere in the world.
2	WAN can cover larger area. It can cover cities, countries and even continents.
3	Data transfer speed is slower in WAN.
4	Transmission     speeds     are     normally 56 kbps to 45 Mbps.
5	The hardware needed for a WAN is more expensive.
6	WAN is usually connected through telephone lines, fiber optic cable or through wireless media.
7	The    connection    in    WAN    may not be permanent.
8	WAN is used to share only data and information like Email and file transfer
9	WAN has more possibility of data transmission error because of long distance.
10	WAN is used to transfer data over long distances.
11	WAN is difficult to install and configure due to connecting computers at multiple and distant sites.
12	WANs are difficult to troubleshoot.

 

ADVANTAGES OF COMPUTER NETWORKS

ADVANTAGES OF COMPUTER NETWORKS

Following are some important advantages of computer networks:

1. Data and Information Sharing

Different employees of an organization can share common information with the help of computer network.

2. Software Sharing

Different software can be shared with the help of computer networks.

3. Hardware Sharing

Different hardware can be shared with the help of computer networks. For example, if there are five computer users in an office, we can save cost by using only one printer with the help of computer networking. In a computer network, only one computer will manage all printing needs of the computer users in a small office. In addition, we can share other hard ware devices like hard disks, CD-Rom Drives / Writers, modems, routers and scanners etc.

4. Money Saving

We can save a lot of money by using computer networking, because of sharing the same software and hardware in a network.

5. Internet Sharing

We can buy only one DSL internet connection and share it with in whole organization with the help of computer networking.

6. Easy Communication Within Organization

We can send and receive messages and files through network. In this way, a file can be moved to one place to another within an organization without the need of a physical worker to take and carry the files to a destination. With the help of a command in a computer we can transfer file within seconds from one room to another.

7. Easy Communication Outside Organization

We can send and receive emails and share files with other people outside organization using internet.

Bus Topology

Bus Topology

Bus topology is the simplest network topology. In bus topology, all computers in network are connected to a common communication wire. This wire is called BUS. Terminators are used at both ends of wire.

 

 

 

 

 

Advantages of Bus Network Topology

1. It is very simple topology.
2. It is easy to use.
3. It needs small amount of wire for connecting computers.
4. It is less expensive due to small wire needed.
5. If one computer fails, it does not disturb the other computers in network. Other computers will continue to share information and other resources with other connected computers.

Disadvantages of Bus Network Topology

1. Only small number of computers can be connected in a bus network.
2. Network speed slows down as the number of computer increases in bus topology.
3. Finding a fault is difficult in bus topology.

 

Star Topology

Star Topology

Star Topology is the most popular and widely used network topology in local area networks. In star topology, all computers are connected with a central device known as HUB or Switch. Now-a-days Hubs are often replaced by Fast Network Switches. The sender computer sends data to the hub. The hub sends it to the destination computer. So, all data communication is managed through HUB or Switch.
Note: The major difference between a Networking Hub and Networking Switch is that HUB sends data to all computers, and the destination computer will accept it while other computers will not. On the other hand, Switch sends data only to the destination computer. Therefore, switch can reduce network traffic and hence provides fast transmission speed.

Advantages of Star Network Topology

1. Easy Installation and maintenance

It is easy to maintain network. That is why it is so popular.

2. Adding or removing computers

Adding or removing computers can be done without disturbing the network. We connect the new computer with the HUB by means of a networking cable. One end of the cable (RJ 45 connector) is inserted in computer’s Network Interface Card and the other end (RJ 45 connector) is plugged into the HUB, and that’s it.

3. Fault Diagnosis

In a star network topology, finding faults is easy. If a computer is no more connected with your network, you can check its cable and connectors or network settings in its Operating system.

4. Network Reliability

Single computer failure will not disturb whole network, since all other computers are connected with separate links ( wires ) to HUB. Definitely, they will work fine.

5. Better performance

Star topology can prevents the passing of data through an excessive number of nodes. By using a Switch, at most, 3 devices and 2 links are involved in any communication between any two devices.
6. Device Isolation
Each device is separately connected to HUB or Switch and is isolated. This is why each device works independently.

Disadvantages of Star Network Topology

1. In star network topology, data communication depends on HUB. If central hub fails, then whole network fails.
2. Since each computer will be connected with HUB by means of a separate wire, star network topology needs more cable to connect computers.
3. It is more expensive due to more wires.

 

Ring Topology

Ring Topology

In Ring topology, each computer is connected to the next computer such that last computer is connected to the first. Every computer is connected to next computer in the ring. Each computer retransmits what it receives from the previous computer. Suppose, computer A needs to send data to computer D. Now the computer A sends data to computer B. As computer B is not the destination computer, so it will retransmit data to computer C. Finally, Computer C will transfer data to computer D, the destination computer. When a node sends a message, the message is processed by each computer in the ring. If a computer is not the destination node, it will pass the message to the next node, until the message arrives at its destination.

Advantages of Ring Network Topology

1. It is relatively less expensive than a star topology network.
2. In a Ring topology, every computer has an equal access to the network.
3. Performs better than a bus topology under heavy network load

Disadvantages of Ring Network Topology

1. Failure of one computer in the ring can affect the whole network.
2. It is difficult to find faults in a ring network topology.
3. Adding or removing computers will also affect the whole network since every computer is connected with previous and next computer.
4. Sending a message from one computer to another takes time according to the number of nodes between the two computers. Communication delay is directly proportional to number of nodes in the network.

 

Tree Topology\

Tree Topology

Actually, a Tree topology is the combination of two topologies: bus and star topology. A tree topology combines the characteristics of bus and star topologies. It consists of groups of computer connected as star topology. These groups are then connected to a central communication medium (bus cable).

 

 

Advantages of Tree Network Topology

1. Many software and hardware vendors support tree topology.
2. It provides point-to-point wiring for individual groups.

Disadvantages of Tree Network Topology

1. If the main backbone line breaks, the entire tree network goes down.
2. It is more difficult to configure and maintain.
3. If any hub fails, related segment will be removed from the network.