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Different Types of Illegal Websites.
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While the Internet can be a phenomenal tool for education and communications, it can also be a dangerous place. Illegal websites are domains that exist to promote or permit illegal activity, or those that go against regional laws or government restrictions. Not all websites have the same status in every region; certain areas may ban websites containing pornography, for instance, which is permissible in other areas.
Pornography websites are frequently the target of illegal website crackdowns. There are several ways in which a pornographic website may be deemed illegal, though many operate on a fully legal basis. First, if pornography or a type of pornography is banned by a country, the website may be illegal in that jurisdiction. Child pornography, for instance, is illegal throughout most of the world and subject to strict punishments for both creating the pornography and viewing or possessing it, such as through downloads. Second, if a website uses copyrighted material without getting the rights, it may deemed illegal and prosecuted for infringement.
Copyright infringement is another major factor in the creation of illegal websites. Books, movies, television shows, and images are all subject to copyright laws, meaning that the creator or his representatives have the sole right to issue copies. File sharing or bit torrent sites, which allow users to upload personal material and download other users' files, are frequent targets of shutdown and prosecution for infringement. These illegal websites may be difficult to discern from legal downloading sites, but generally legal sites rely on owner distribution, rather than peer-to-peer sharing, of files.
Fraudulent websites are also illegal websites that can quickly make victims out of unsuspecting users. These sites may sell fake products or offer fraudulent services, or be set up as a mirror site to a real website. The goal of most of these websites is to get users to enter personal information, such as bank account or credit card numbers, which can then be stolen and used. Phishing scams, which send out emails that appear legitimate asking a user to update his or her information with a company they have an account with, frequently create this type of website to trick the user into believing that his or her information is going to a trusted group instead of scamming thieves.
Website legality may depend entirely on the geographical location of the user. Generally, countries with less emphasis on freedom of information will have more strictures on what websites are permitted within their boundaries. In China, for example, some of the most popular websites in the world, including social networking sites, search engines, and video uploading sites, are banned by the government. This can cause complications for travelers who are surprised to find some of their favorite places deemed illegal websites, and can even lead to prosecution if access is somehow made to a site that is banned. Generally, access is difficult to obtain, as regional Internet providers will block the availability of illegal websites throughout their network.
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UNIT 4
Database
Data Storage.
The term data storage can refer to anything with information recorded on it. Using this broad definition, a hardback volume of an encyclopedia, an audio cassette of a pop song, and even a piece of paper with random words written on it would all be considered examples of data storage. The most popular definition of the term limits it to only the storage of information on computers and similar devices.
Everything a computer “knows” or is able to “know” is called computer data. This includes e-mails, text files, digital pictures, and databases. Computer data storage can be divided into two main categories: primary and secondary. Each is important, but the secondary type is usually what people think of when they use the term. Both categories will be explained below.
What a computer “knows” at any given time is technically what information a computer’s central processing unit (CPU) can directly access. This information is called memory, and the components that store it are considered primary data storage. Memory is mainly stored on Random Access Memory (RAM). There are many types of RAM, but they usually come in the form of modules that plug into a specific slot inside the computer. This type is constantly being erased and rewritten, most often from secondary storage.
Secondary data storage represents all of the other types not included in the primary storage. Though some experts previously used an additional category called tertiary, technological advances have blurred the differences between the secondary and tertiary levels to the point that only one term is necessary. Internal hard disk drives, CD-ROM disks, and flash memory sticks are all examples of this type of storage. There are so many different types that this category can be further divided into three different areas: on-site, removable, and off-site.
On-site data storage represents any type of storage device that is designed to remain with the computer or at a single location where the computer is housed. The most common on-site device is a hard disk drive, and it is included in almost every personal computer. Solid state drives and network attached storage are also examples of such devices.
Removable data storage is any type that is designed to be easily removed from a computer. This type has become more common than on-site types in modern times. The big disadvantage of this type used to be that data access time was much slower than on-site, but speed improvements have decreased this penalty to within acceptable limits for many common applications. CD-ROMs, DVD-ROMs, USB flash drives, and portable hard disk drives are all examples of removable data storage.
Off-site data storage is one of the most recent types of storage. In this type, information is stored away from the computer at a distant location. This data can then be accessed either by a direct call or through the Internet. This type of storage has the advantage of being available if something happens to the on-site computer system.
There are disadvantages to off-site storage compared to other types, both because of how long it takes to access the data and because it can be less secure. Examples of off-site data storage include electronic vaulting, on-line file hosting services, and on-line photo sharing websites. This type is also a primary aspect of cloud computing.
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Data Storage Device.
A data storage device is any mechanism used to record data so it can be retrieved and used later. The term most often is used in the context of computers or other electronic technologies for which information needs to be copied to a mobile storage unit or saved to a medium for long-term storage. Internal, non-removable devices such as computer hard drives, compact disk (CD) drives or digital video disk drives (DVDs) that can read and write information to a disk also can be referred to as a data storage device. Less commonly, a data storage device can refer to a mass storage drive that is designed to encode and hold a very large amount of information, such as all the information within a corporate network, on some type of media such as a magnetic tape reel or an optical disk.
There are two types of data storage devices, one that holds information permanently and one that holds information only as long as power is provided to the mechanism. Inside a computer, random access memory (RAM) microchips or embedded circuit-based memory are examples of temporary forms of storing data, also called volatile memory storage. The primary purpose for volatile data storage is to provide an area where a device can quickly access information — such as code for an application — which does not necessarily have to be saved once the device is turned off or reset. This volatile information is often copied or compiled from data stored on a permanent data storage device.
A permanent data storage device is designed to hold information for the life of the medium, regardless of whether the unit is actively powered. Computer hard drives that write to spinning magnetic disks are one of the most common forms of non-removable devices. A CD or DVD drive is another example and, although they are sometimes non-removable, they write to disks that can be removed and read by another computer or other device.
One of the most used types of data storage device is known as a solid state drive or, more commonly, a flash drive. This type of device is often a self-contained, portable drive that can hold a certain amount of information and can be used on nearly any computer or device with a universal serial bus (USB) drive. The popularity of solid state drives comes from the fact that they do not have any moving parts, making them more resistant to damage, especially in mobile devices. One drawback to using a solid state drive is that, while the technology is very fast, small and efficient, it also wears out over time, meaning a drive will eventually become prone to errors and, ultimately, unusable.
UNIT 5
E-Commerce.
Electronic commerce, or e-commerce, refers to economic activity that occurs online. E-commerce includes all types of business activity, such as retail shopping, banking, investing and rentals. Even small businesses that provide personal services, such as hair and nail salons can benefit from e-commerce by providing a website for the sale of related health and beauty products that normally are available only to their local customers.
Easy for Businesses
Although e-commerce once required an expensive interface and personal security certificate, this is no longer the case. Virtual storefronts are offered by a variety of hosting services and large Internet presences that offer simple solutions to vendors who have little or no online experience. Tools for running successful e-commerce websites are built into the hosting servers, eliminating the need for the individual merchant to redesign the wheel. These tools include benefits such as virtual shopping carts, inventory and sales logs and the ability to accept a variety of payment options, including secure credit card transactions.
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Security Improvements
Early e-commerce was stunted by security fears, but improved technology has made millions of people worldwide feel comfortable buying online. Seeing the vast potential in online commerce, most credit card companies helped allay fears by guaranteeing that cardholders would not be held responsible for fraudulent charges as a result of online shopping. All of these factors have helped e-commerce become a booming industry.
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, it’s 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
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 to 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.
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.
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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.
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