Convenient for Shoppers
The popularity of online commerce is understandable, considering the time and hassle involved in running from store to store, searching for an item. It not only takes valuable time and energy, but using transportation usually costs money. Shopping online whenever the mood strikes even in the middle of the night has many advantages. Not only is it convenient to shop at a myriad of vendors from the comfort of a computer chair, its also a snap to find the best deal by allowing certain shopping sites to sift through all of the sellers.
Prices Often Lower
E-commerce also has other advantages. Employee overhead is virtually nonexistent, and the cost of operating a website usually is nominal, especially when compared with the cost of storefront property. To top it off, most transactions are handled by software processes, never requiring a real person until the item is ready to be packed and shipped. This translates into real savings to the customer. As a result, physical businesses often cannot compete with their online counterparts, although consumers do have to watch for inflated shipping fees that might negate the savings of buying online.
UNIT 6
Networks.
6.1 Types of Networks.
The types of networks are categorized on the basis of the number of systems or devices that are under the networked area. Computer Networking is one of the most important wings of computing. Networking is the process by which two or more computers are linked together for a flawless communication. By creating a network, devices like printers and scanners, software, and files and data that are stored in the system can be shared. It helps the communication among multiple computers easy. By computer networking the user access may be restricted when necessary. There are some types of networks:
1) Peer-to-peer network: In this networking system all computers are given equal importance. All the software and data are stored on each computer and accesses to them are given to each user. In a peer-to-peer network, network hosts don't have a specific role. They provide network services and they also consume network services. In a peer-to-peer network we can have hosts that will fulfill a variety of different roles. For example, one computer can have a printer connected to it which is shared on the network. Another computer can have a large hard drive installed and everyone is allowed to put files on that hard drive. So, in this situation we have hosts that both provide and consume network services. In essence, they function both as a client and as a server at the same time. The main benefit of peer-to-peer network is the ease of installation. All we have to do is share our resources on the network. It's also very inexpensive. Of course, there's some drawbacks to a peer-to-peer network. First of all, a peer-to-peer network is not very scalable which means that the bigger it gets, the harder it is to manage it. That's because they lack centralized control.
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2) Local Area Network: The Local Area Network is also referred as LAN. This system spans on a small area like a small office or home. The computer systems are linked with cables. In LAN system computers on the same site could be linked.
3) Wide Area Network: A Wide Area Network or WAN is a type of networking where a number of resources are installed across a large area such as multinational business. A wide area network is a group of interconnected LANs, Local Area Networks that are separated geographically. Through WAN offices in different countries can be interconnected. Sometimes, user from one city needs to access some data that is located on a server in another city. To make that possible we've connected them in some way so that these local area networks are inter-networked together, making a very large internet work, or a wide area network. The best example of a WAN could be the Internet that is the largest network in the world. In WAN computer systems on different sites can be linked.
4) Client Server: Another classification within the host roles category is a client server network. In a client server network, unlike a peer-to-peer network, network hosts have specific roles assigned to them. We have certain systems, certain hosts that are assigned to be servers. A server provides network resources. On a client server network we also have clients. A client does not provide network services, it only consumes network services. Clients will not have, for instance, shared storage or printers. All those services are provided by the server. Server provides the resources, the client simply use the resources. With a peer-to-peer network everybody had the same operating system, but in client server network client workstations have generic operating systems that provide functionality. For example, clients could have Windows XP or Windows 2000 installed. Servers would have some special optimized operating system like Server 2003. These operating systems are designed to provide these network resources and are not designed for client type tasks. The main benefit of this type of network is that it's very highly scalable. That means it's very easy to expand the size of the network, it's very easy to add more clients and it's very easy to add more servers. Client server networks are also much easier to support. That's because services are centralized. If we know where all the services are, we know where to look when we have some problems with them. Backup is also a lot easier. We can configure that users store their data on the server. That way, instead of having to back up individual workstations we only need to backup one location - the server. There are some drawbacks. Operating systems for servers are fairly expensive (the exception, of course, is Linux). The other thing is that this type of network takes a lot of planning. We have to decide which servers are going to host which services, where they're going to be placed on the network, etc.
6.2 What is a Network Administrator?
Network administrators are professionals who are charged with the responsibility of maintaining a computer network. The administrator will oversee the installation and updates to any software as well as install and maintain any hardware needed to operate the network. It is not unusual for a network administrator to be consulted when upgrades in hardware or software are required to create a new network or enhance an existing one.
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The typical computer network administrator will possess some type of higher degree connected with Information Systems and Computer Science. In addition, the administrator is often trained on the function of specific hardware or software that is included as part of the network. This makes it possible for the network admin to quickly master any new additions to the network or even build a network from scratch.
In order to carry out his or her responsibilities, the network administrator will have master access credentials that allow the admin to interact with any function within the system. This means network admins can handle processes such as the creation of network addresses, the assignment of routing protocols, configure routing tables, and establish any type of security measures necessary to protect the network. Typically, the credentials of the network administrator override all other access privileges enjoyed by others in the organization, allowing the admin to troubleshoot when there is a need to monitor activity of a specific user or change access protocols for any reason.
Many companies choose to hire an in-house network administrator. This can be helpful when the size and function of the company require someone to be on site to handle hardware and software installations, run diagnostics, assign privileges and in general maintain the network. The administrator is also able to provide input on the purchase of new hardware or software, making recommendations for products that will enhance the productivity of employees. In some cases, the administrator may also be called upon to modify the configuration of software in order to adapt it to the specific applications needed by the company.
Smaller businesses may choose to outsource network administration functions. Today, it is not uncommon for an Information Systems professional to provide administrator services to a number of clients. While not on site, the service provider can be called upon when there is the need to alter the network in some manner, deal with performance issues, or assign new access credentials to new employees. With this type of outsourcing service, the client normally pays the network administrator a fixed monthly fee for covered services, with provisions for additional fees when specialized projects are required.
What Are the Different System Administrator Jobs?
What is a Network Administrator? ()
System administrator jobs include a number of different functions. There are also related career opportunities that a person interested in working in this area may want to consider. Other than working as a systems administrator, they may want to learn more about the duties performed by a network administrator, a database administrator, and a web administrator.
The system administrator is a person with a good understanding of how computer operating systems work. He must also be well-versed in computer hardware and software applications. People working in system administrator jobs must also have good troubleshooting skills, since part of their job description is to diagnose problems and correct them. Being able to work well under pressure is another important trait, since no business can afford to have its computer system down for any length of time without productivity being affected.
A person who is working as a network administrator focuses their attention on the company's Local Area Network (LAN). They are responsible for setting up and installing the LAN. Once it's up and running, the network administrator also looks after making sure that it remains functional by performing regular maintenance checks on the LAN.
The network administrator is also responsible for investigating any problems that users are having with the LAN. He or she analyzes the situation and implements a solution. Good communication skills are also required, since the network administrator is also responsible for conducting training sessions so that new employees can work with it effectively. Follow-up sessions for existing employees are also conducted by the network administrator to ensure that all staff is using the technology effectively.
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People who are looking at system administrator jobs may want to consider becoming a database administrator. This professional is responsible for taking the information that an organization collects and devising a way to organize and store it. The database administrator may also be involved in backing up the data or in implementing security measures.
Another example of a career choice related to system administrator jobs is that of web administrator. The person who works in this capacity is responsible for ensuring that a company web site is functioning properly. They also look after connectivity issues between the company web site and its network. The web administrator also monitors the company's e-mail functions. Making sure that firewalls are functioning properly is another part of the web administrator's job description.
UNIT 7
Security solutions.
7.1 Information Security.
Information security is the process of protecting the availability, privacy, and integrity of data. While the term often describes measures and methods of increasing computer security, it also refers to the protection of any type of important data, such as personal diaries or the classified plot details of an upcoming book. No security system is foolproof, but taking basic and practical steps to protect data is critical for good information security.
Password Protection
Using passwords is one of the most basic methods of improving information security. This measure reduces the number of people who have easy access to the information, since only those with approved codes can reach it. Unfortunately, passwords are not foolproof, and hacking programs can run through millions of possible codes in just seconds. Passwords can also be breached through carelessness, such as by leaving a public computer logged into an account or using a too simple code, like "password" or "1234."
To make access as secure as possible, users should create passwords that use a mix of upper and lowercase letters, numbers, and symbols, and avoid easily guessed combinations such as birthdays or family names. People should not write down passwords on papers left near the computer, and should use different passwords for each account. For better security, a computer user may want to consider switching to a new password every few months.
