The public domain is a large overview term, for any thing, usually a creative work, that can be freely used. For example, the Bible is a public domain work. It can be used, copied, sold, quoted, translated, or altered without infringing on anyone’s copyright or patent privileges. Examples of public domain software include the GNU/Linux software, which forms a part of many PC operating systems.
While you can find lists of public domain software, you are more likely to find lists of free software. In most cases, this software is not really in the public domain. Your obtaining it means that you have acquired a license to use it. If you’ve ever installed a computer program for free, you probably had to accept terms and conditions for using the software. Some of these terms you agree to may prohibit you from selling, altering, or profiting from the software in any way.
There are a number of free software programs that are not public domain software. For example you can easily get copies of Adobe Reader, Netscape, Internet Explorer and a variety of other programs. Also, when you purchase a computer, you may be given several free programs, but again these are licensed to you only, rather than being yours to copy or distribute, as would be public domain software.
You can find public domain software in a variety of locations. The UCLA library offers numerous downloads and catalogues. Some of the most interesting public domain software is key to the sciences. Programs like WebLab and Visual Molecular Dynamics allow you to create three-dimensional drawings of molecules. A great place to look for public domain software, and free or shareware is the Free Software Foundation (FSF). You’ll find lists of public domain software, and any software that grants you automatic licenses to use specific programs. The FSF is also specific in telling you whether you are downloading freeware or public domain software.
There are often references to books and other printed matter that has entered public domain. What this means is that while the printed works were at one time copyrighted and therefore considered the intellectual property of the author and publisher, that is no longer the case. In many cases, the work is no longer in print by the original publisher, the author is deceased, and the copyright was allowed to expire. In effect, the work is no longer owned by a person or entity. When no ownership can be established, the work is considered to be in the public domain.
Along with printed matter, the same general principle applies to early motion pictures that were made before 1922, or were produced by studios that no longer exist. When there is no evidence that someone today is the beneficiary of those works and can reasonably claim ownership of the films, they are considered to be in the public domain. This means that anyone can obtain a copy of the film and reproduce multiple copies for sale without infringing on the rights of anyone.
In addition to works that were once copyrighted but no longer enjoy that status, there are works intentionally created for general public use. Some government documents are an excellent example of this type of public domain product. Unless there are disclaimers to the contrary, government documents are understood to be accessible and usable by everyone, without the need to observe a copyright. Generally, however, it is anticipated that if a section of the document is quoted, the quote will be referenced properly.
As a broad definition, public domain materials are any form of knowledge that is freely available to the general public, and carries no restrictions on the use of the materials. Books, movies, and other forms of printed matter are all common examples of public domain information, but essentially any device that previously enjoyed a copyright but is no longer covered would be considered to be in the public domain.
The DNS system was devised as Internet use expanded, and researchers realized that having to type in numerical addresses could be challenging for some users. Under this system, which is administered by the Internet Corporation for Assigned Names and Numbers, users can type in words or assortments of characters which are easier to remember than strings of numbers. Each domain includes a top level, second level, and third level or subdomain.
The creation of domain names also allowed businesses to brand themselves more effectively. Instead of telling people interested in Volkswagon cars to go to a specific number address, for example, the company could tell customers to go to volkswagon.com. The DNS system is sometimes compared to the phone book, because it allows people to look up a person, product, or service by name, rather than having to remember the right number.
A web address such as www.wisegeek.com is considered a domain name. The first part of the address, the “www,” is the third level or subdomain.“wisegeek” is the second level, and the “com” is the top level domain. Individual domain owners can create multiple subdomains under their second level domain, such as the subdomain “example” in example.wisegeek.com. Many people refer to second level domains as “domain names” because people often reference sites by the second level domain alone. However, multiple sites could have the same second level and different top level domains, which makes it important to spell out a domain name in full to avoid confusion.
Top level domains such as “com,” “org,” and “net” are generic. Anyone can register domain names in any of these top level domains. Some other generic top level domain options like “edu,” “gov,” and “mil” are restricted to people who can prove that they have a legitimate reason to use them. Top level domains sorted by country code, such as “ie” for Ireland, are also available, as are sponsored domains controlled by various industries.
When someone wants to register a new domain name, he or she has a choice of top level domain, assuming that those domain names are not already taken, and that he or she is authorized to use a particular domain. Some people like to get creative with top level domain names, as in the case of the social bookmarking site Delicious, which registered the domain icio.us so that it could create the subdomain “del” and spell out del.icio.us with its domain name.
A parked domain includes one simple page. If the site is intended for development, the page will indicate it is under construction or coming soon. Domain parking can be renewed annually, and there is no deadline as to when a site need be developed. You might find you don’t have time, or you might decide to let the domain expire at the end of the contract, typically one year. In this case, the only investment lost is a few dollars.
If you decide to develop your domain, you will need to pay for hosting services at that point. The right hosting service will provide enough space for your website and any special scripts or services you require. Once the domain is being hosted, it is no longer parked.
If you already have a successful site, another use of domain parking is to secure addresses similar to your main website and redirect traffic there - an inexpensive way to protect your website. For example, wiseGEEK.net redirects traffic to the proper site, wiseGEEK.com. The first domain is parked. The parked domain need not reside on the same host server as the main website.
Some people use domain parking for the sole purpose of ‘re-selling’ the address - transferring ownership to a buyer for a fee. This occurred more in the early days of the Internet, when major companies had yet to arrive and were willing to pay a high price for their trademark names. Laws were eventually enacted to protect trademarks, but a parked page can still advertise the sale of a domain.
If interested in domain parking, keep in mind a few considerations. Most domain registrants offer hosting services, but you may or may not want the domain seller to host the domain once it is no longer parked. Be sure to check that the domain seller does not retain any rights to the domain. The buyer should have the power to control the domain’s registration information, and most importantly, the ability to transfer the domain to an independent hosting service when and if desired. Check to see whether a fee is associated with transferring the domain.
The process of multi-homing makes use of what is known as Stream Control Transmission Protocol, or SCTP. Essentially, the process involves employing multi-homing by making use of a single SCTP endpoint to support the connectivity to more than one IP Address. By establishing connection to multiple addresses, multi-homing can help to enhance the overall stability of the connectivity associated with the host.
One of the advantages of multi-homing is that the computer host is somewhat protected from the occurrence of a network failure. With systems that make use of a single IP address and connection, the failure of the connected network means that the connection shuts down, rendering the end system ineffectual as far as connectivity to the Internet is concerned. With multi-homing, the failure of a single network only closes a single open door. All the other doors, or IP addresses associated with the other networks, remain up and functional.
In general, multi-homing is helpful for three elements of effective web management. First, multi-homing can help to distribute the load balance of data transmissions received and sent by the computer host. Second, the redundancy that is inherent to multi-homing means less incidences of downtime due to network failure. Last, multi-homing provides an additional tool to keep network connectivity alive and well in the event of natural disasters or other events that would normally render a host inoperative for an extended period of time.
Multi-homing is often employed in situations where access to the Internet is critical to the operation of a business related effort. For example, multi-homing will be included as part of the disaster recovery initiatives that many financial institutions have in place. By creating network redundancy, it is possible for banks, brokers, and investment firms to remain accessible to customers even when some type of unanticipated event has crippled the primary network interface.
Servers are powerful computers that have extremely large hard drives, or an array of hard drives. Space is then rented to those who want a "website presence" on the Internet.
Every server on the Internet has a unique numerical IP address. You can think of servers as apartment buildings with unique addresses. Each apartment unit within each building is equivocal to space rented out for individual websites. And like real apartment buildings, each unit also has an address based on "the building" in which it is located.
When you rent a space on a server then, you're setting up house on the Internet. You can be reached by a unique address (the website address), which is based on the server's address.
There are many different types of web hosting. Most packages come with certain capabilities for users. Examples are scripts that allow interactive functions, forms, bulletin boards etc. For professional purposes there are also Web hosting services that offer commercial packages that bundle business tools, like point of sales packages and credit card processing.
Prices for Web hosting vary from free to hundreds of dollars a year, depending on your needs. Web hosting for personal websites that don't require any special tools and have low traffic (not a high number of viewings) can be found easily for free.
Free Web hosting is convenient but has its drawbacks. Usually it will be required that you allow the server to run advertisements on your website. The advertisements are normally banner ads -- a banner at the top of the page for example -- and sometimes pop-up ads as well. Most free hosting services offer an alternative pay-plan to have the advertisements removed.
Another consideration is that free services normally allocate your website address as an extension of the server's address. For example: www.thewebhost.com/yourwebsite. If you want an address like: www.yourwebsite.com, you will have to pay to register your own domain name.
There are other considerations when looking for a Web host aside from price. Some hosting services have policies that restrict certain content, scripting languages, functions or uses. You should also read the privacy policy of any hosting service that you are considering, to see how they will use the personal information you provide to them in setting up your account.
The term "Web 2.0" is commonly associated with web applications which facilitate interactive information sharing, interoperability, user-centered design and collaboration on the World Wide Web. Examples of Web 2.0 include web-based communities, hosted services, web applications, social-networking sites, video-sharing sites, wikis, blogs, mashups and folksonomies. A Web 2.0 site allows its users to interact with other users or to change website content, in contrast to non-interactive websites where users are limited to the passive viewing of information that is provided to them.
The term is closely associated with Tim O'Reilly because of the O'Reilly Media Web 2.0 conference in 2004.Although the term suggests a new version of the World Wide Web, it does not refer to an update to any technical specifications, but rather to cumulative changes in the ways software developers and end-users use the Web. Whether Web 2.0 is qualitatively different from prior web technologies has been challenged by World Wide Web inventor Tim Berners-Lee who called the term a "piece of jargon"
A single microprocessor is like a miniature skyscraper with stairway-like circuits between each floor. Hundreds of these "skyscrapers" can be produced on a silicon wafer at a time.
From start to finish, a microprocessor takes about 2 months to produce. Fabrication begins with a very thin slice of silicon. Over 300 manufacturing steps later, this silicon wafer holds hundreds of microprocessors. If you could enlarge the wafer to the size of a swimming pool, the surface would look like a miniature city.
Now think small and ask yourself this: How are such tiny circuits put in such a small chip? Good question. No mechanical object or pen could lay down such incredibly microscopic wires. Instead, the pathways for the current are created by using solvents to remove channels of material. These microscopic channels are then etched with chemicals and implanted with electrons to make them conduct electricity.
Pluck a hair from your head. (Really.) Now look at it. It isn't very thick, is it? Well, to a microprocessor manufacturer, that hair looks like a telephone pole. That's because a hair is more than 2000 times wider than a transistor on a microprocessor. Wires between transistors are even thinner. They're more than 4000 times thinner than a hair.
How big is a human hair? About 100 microns in diameter. That means a transistor is just 0.045 microns wide.
What's a Micron ? It's a very small metric measurement. You're probably familiar with centimeter marks on a ruler. (If not, go look at one.) A micron is .0001 of a centimeter.
A microprocessor transistor then is 0.0000045 centimeters wide. (Want that in inches? It's 0.00000177 of an inch.)
