What are the differences between a virus and a worm?

A computer virus is a small program written to alter the way a computer operates, without the permission or knowledge of the user. A computer virus must meet two criteria:

1. It must execute itself. It often places its own code in the path of execution of another program.
2. It must replicate itself. For example, it may replace other executable files with a copy of the virus infected file. Viruses can infect desktop computers and network servers alike.

Most viruses are purposely programmed to damage the computer by destroying programs, deleting files, or reformatting the entire hard disk. Others are not designed to do any damage, but simply to replicate themselves and make their presence known by presenting text, video, and audio messages. Although these benign viruses do not create notable problems for the computer user, but they typically take up computer memory used by legitimate programs. As a result, they often cause abnormal behavior and can result in system crashes. In addition, many viruses are bug-ridden, and these bugs may lead to system crashes and data loss. There are five recognized types of viruses: file infector viruses, boot sector viruses, master boot record viruses, polypartite viruses and macro viruses. Some viruses are called Trojan horses. Trojan horses are impostors that claim to be something desirable but, in fact, are malicious. A very important distinction between Trojan horse programs and true viruses is that they do not replicate themselves. Trojan horses contain malicious code that when triggered cause loss, or even theft, of data. For a Trojan horse to spread, users must invite these programs onto their computers; for example, by opening an email attachment or downloading and running a file from the Internet.

Worms are programs that replicate themselves from system to system without the use of a host file. This is in contrast to viruses, which requires the spreading of an infected host file. Although worms generally exist inside of other files, often Microsoft Word or Excel documents, there is a difference between how worms and viruses use the host file. Usually the worm will release a document that already has the “worm” macro inside the document. The entire document will travel from computer to computer, so the entire document should be considered the worm.

Worms are considered more dangerous because of their ability to spread rapidly through the network without any human action. In fact, a computer virus harms an individual PC and so its damage is more localized. Due to the copying nature of a worm and its capability to travel across networks the end result in most cases is that the worm consumes too much system memory or network bandwidth, causing web servers, network servers and individual computers to stop responding.

As a Systems and Network Administrator, why I should understand telecommunication?

Telecommunication is essential to smooth operations in today’s business world, is the transmittal of data and information from one point to another. Thus telecommunication is communications over a distance. Development in the field of telecommunications has been very rapid in recent years. By telecommunications I mean here all processes that render it possible to transfer voice, data and video with the help of some form of electromagnetic system, including optical transfer methods.

As a Systems and Network Administrator, I will have to provide installation, administration and support service for the organization’s telephone systems, integrated voice/data/video network and related technologies. Implement, tune, configure and upgrade telecommunication systems and network for ensuring optimal performance as well as my organization would maximizes its benefits from fast and reliable telecommunication. For these reasons, it is essential that I understand the fundamental promises and limitations of networking and telecommunications.

While people can enjoy technologies without understanding how they work, educated Systems and Network Administrator often does need to understand some fundamental concepts to be able to participate in decision making when selecting networking equipment and services.

The Systems and Network Administrator manages networks, so it is vital that I should know what a network is made of. The network obviously includes the routers, switches, modems, and data services like ISDN lines and ATM, frame relay, or ADSL links. As a Systems and Network Administrator, one of my tasks is to help organization to reduce communication cost.

Knowledge of and familiarity with Data Management is crucial

Organizations recognize data as a critical asset. Available and reliable information is the most important resource of any business in any industry. A productive Systems and Network Administrator must know how databases and data warehouses are built and queried, and what types of information can be extracted. The professional Systems and Network Administrators sometimes must communicate with database designers and must be able to tell how data elements relate to each other, how they would like the data to be accessed, and what report they need.

There are many topics within data management; some of the more popular topics include data recovery, data modeling, data mining and data warehousing:

• Data RecoveryData Recovery is exactly what it sounds like – a way to recover important information that was lost from a computer crash, hard disk malfunction, or virus attack. No matter the scale, big corporation database recovery or single user retrieval of files from spontaneous “deleting”, data recovery is an important and necessary part of any operating system. Data Recovery software can be developed, installed and removed from existing systems to retrieve lost data or partial data and minimize damage caused to the system.
• Data ModelingData modeling is the process of structuring and organizing data. These data structures are then typically implemented in a database management system. In addition to defining and organizing the data, data modeling may also impose constraints or limitations on the data placed within the structure. Managing large quantities of structured and unstructured data is a primary function of information systems. Data models describe structured data for storage in data management systems such as relational databases. They typically do not describe unstructured data, such as word processing documents, email messages, pictures, digital audio, and video. Early phases of many software development projects emphasize the design of a conceptual data model. Such a design can be detailed into a logical data model. In later stages, this model may be translated into physical data model.
• Data MiningData mining involves the use of sophisticated data analysis tools to discover previously unknown, valid patterns and relationships in large data sets. These tools can include statistical models, mathematical algorithms, and machine learning methods. Consequently, data mining consists of more than collecting and managing data, it also includes analysis and prediction.
• Data WarehousingA data warehouse consists of a computer database responsible for the collection and storage of information for a specific organization. This collection of information is then used to manage information efficiently and analyze the collected data. Although data warehouses vary in overall design, majority of them are subject oriented, meaning that the stored information is connected to objects or events that occur in reality. The data provided by the data warehouse for analysis provides information on a specific subject, rather than the functions of the company and is collected from varying sources into one unit having time-variant.