| Password |
A secret word or unpronounceable string of characters that protects the security of a Username. In most computer systems passwords are not shown whilst being typed and they cannot be seen by anyone, even the system administrator, even if the administrator has the power to change or override the password (which is almost always the case). Finding out passwords, or how to bypass them, is a favourite pastime of Crackers. The easiest passwords to "crack" are words that can be looked up in a dictionary. There are fewer than 50,000 words in the very comprehensive 2" thick Concise Oxford Dictionary. The average Sun reader's vocabulary is less than 10,000 including f-words. It doesn't take a computer long (operating as they do, at hundreds or thousands of millions of instructions per second) to look up and try 50,000 words, and then try every word in combination with every other, and then try all those in combination with every reasonable date of birth, possible post code, likely car registration and a very long list of people names, pet names and place names. This is known as a "brute force" attack, but it isn't the only way of compromising passwords. The easiest way is to write them on Post-Its and stick them on the screen, which is why most security breaches are internal, and nothing to do with Hackers or crackers. |
| Path |
All computers have filing systems that store information in an organised way. A "path" is simply a way of describing the precise location in which a piece of information is stored, as in "Technology Block, top floor, first room on the left, 3rd filing cabinet, bottom drawer, folder named Lesson Plans, file called Term 2 Week 6". In computer terms this might be: "/TechBlock/TopFloor/Left1/Cabinet3/Bottom/LessonPlans/Term2Week6.html". Everything up to, but not including, the name of the document itself (Term2Week6.html) is called the "path". If this path and document is on a Web Site, then the path will be preceded by the Web site address. Normally it is not necessary to know the path of a document, just the address of the Web site, because you will reach individual documents by clicking on Links. However, if you do want to use a document's path, it is important to note that the path on many Web Servers is ~Case-Sensitive~, even though the Web site address is not. |
| PC |
Literally, "Personal Computer", but in normal usage it refers only to "IBM-compatible" computers, meaning computers that are able to run the Operating System that the original 1980 "IBM Personal Computer" or "IBM PC", ran. Nowadays the term PC is often used to distinguish between IBM-compatibles and other types of desktop computer such as Macs. PCs normally run Windows, but can also run Linux and several other operating systems. Although PCs can be used to help the intellectually-challenged, thanks to Microsoft most "normal" people find using their PC is something of an intellectual challenge. Unquote. |
| PDF |
Portable Document Format - A wonderful computerised document format that has become the Internet de facto standard, because the free reader (usually called Acrobat Reader) is available in versions to suit almost every type of computer on the planet. The documentation for most Hardware and a lot of Software is delivered in PDF format. There are now many alternatives to the original Acrobat software for converting documents into PDF format, including much cheaper but more basic products such as pdfFactory and Jaws PDF Creator (which we use). There are also alternative readers, but not nearly as many, simply because the "real thing" is free. Anyone publishing facsimile or formatted documents on their Web Site should do so as PDFs, not as Word documents for example. RS infotech provides its clients with documentation in PDF format in addition to paper copies. PDFs can be optimised in various ways, e.g. to minimise size at the expense of quality. They can also easily be protected against copy/paste and/or printing, making them ideal for restricted-use applications. For the technically-minded: PDF is a superset of PostScript, the preferred language of high-end printers. Many such printers convert PDFs back into PostScript, so can print a very accurate version of the original document, but even an ordinary printer can print a PDF to a fairly high standard. PDF is one of the very few truly "universal" technologies that overpowers even the might of Microsoft to whom, incidentally, its very concept is anathema (unless they had thought of it first, which by its very nature they couldn't have, thank <insert omnipotent icon>). |
| Peer-to-Peer |
An alternative to the Client/Server approach. It translates to the Orwellian scepto-concept that "all computers are equal, but some are more equal than others". In terms of a Network it usually means a small basic network without a dedicated Server. In a peer-to-peer network each computer can act as both a client and a server, by "sharing" its own resources and using the "shared" resources of the others. For instance computer "Doc" may be the main store for documents, computer "Fax" may have a fax/Modem whereas computer "Print" may have the best printer. A user on "Print" could work on a brochure stored on "Doc", while a user on "Doc" could print a letter on "Print's" printer then fax it via "Fax's" fax/modem. All this only works if all the "sharing" computers are switched on. A slightly different usage of the term refers to Internet file-sharing systems such as as KaZaA and Grokster, in which there is no central Server and each client computer is able to both Upload and Download files to other members. The advantage of this system is that no one commercial user/computer is readily identifiable as a copyright breacher in the way that Napster was in the late 90's. The disadvantage is that in reality nobody is accountable for the content of the downloaded files, so nastiness and deceipt are rife. |
| Perl |
A free and commonly-used programming language which is well suited to handling text, and so is often used on Web Servers. Perl is not tied to a specific Operating System, and is available in versions to suit many types of computer. Perl is not an ideal beginner's language since it is syntactically close to Unix shell scripts and C, i.e. it looks like gobbledygook to the uninitiated. Perl scripts usually end in ".pl". Common alternatives to Perl include: PHP (as used for this Site) and Python. |
| PGP |
Pretty Good Privacy - A form of "PKI" Encryption that is popular on the Internet, partly because it is now a Web Standard (in the form of "OpenPGP") and it is free or cheap for most purposes. PGP is mostly used for sending e-mails in a non-eavesdroppable form. When used properly it is so good that its inventor was investigated by the US government for "illegal export of munitions", which was a tacit admission that government cryptologists couldn't crack the code. Apparently they still can't, although the criminal case was dropped in 1996 and, reluctantly, the US cryptographic export rules were relaxed in 2000 because they were easily circumvented. See also SSL. |
| Phishing |
An increasingly common method of identity theft, i.e. fraud, made possible by people's stupidity and/or ignorance. Basically, an E-mail arrives, claiming to be from your bank or similar and spinning a tale about security breaches or changes and updates and how you now need to fill in your security details including account number, password, PIN etc and e-mail it back to the sender for verification. A bit like someone ringing you up claiming to be from your phone company and asking you what your name, address and phone number is and when will you be going out. But people fall for it. Reputable organisations will NEVER ask you to send them such security-sensitive details by e-mail, because normal e-mail is inherently insecure. see also PGP. |
| PHP |
PHP: Hypertext Preprocessor - The recursive name is not particularly helpful. PHP is a programming language designed to run on Web Servers and primarily intended to produce sophisticated Web Sites by generating HTML "on-the-fly". PHP is Open Source and free, and is available for most types of Web server. PHP is particularly good at talking to databases, and can be used with a far wider selection of databases than Microsoft's ASP for example. PHP is very widely supported by Web Hosting providers. Parts of this site are written in PHP. |
| PICS |
Platform for Internet Content Selection - A W3C Web Standard for the labelling of content according to rating schemes, much like the BBFC's film classification certificate that shows whether a film is U, PG, 15, 18 etc. PICS labelling however does not have the backing of any laws - its use is entirely voluntary and relies on the goodwill of individual Site policy-makers. |
| PKI |
Public Key Infrastructure - A general term covering cryptographic methodologies (scrambling systems) that have both a Public Key and a Private Key, as opposed to the old-fashioned "secret agent code book" style where anyone who knew "the code" could scramble and unscramble messages. Every cryptographic system has its weakness, and PKI's is that you need to be sure that the public key really belongs to the person you think it does, which is why the concept of "key escrow" was developed: a company independently trusted by both the sender and the recipient is given the job of holding and distributing the public key. It doesn't take too much imagination to realise the potential conflicts of interest, especially if the escrow agent is a commercial organisation (beholden to shareholders, not governments) and the secret data has very high importance (i.e. value). See also GPG, PGP. |
| PKZip |
The name of the Compression method and the original Application used for the Zip file format. |
| Platform |
Generally means an Operating System (e.g. Windows 9x), but it can also refer to a combination of an OS and a specific type of Hardware (e.g. Linux on Intel), or just to the hardware (e.g. IBM AS/400). |
| Plug-In |
An extension to a computer application that gives it extra capabilities. Plug-ins are often created by third parties, rather than by the application's designer. Browsers usually have several plug-ins installed to enable them to display material that they otherwise couldn't. A well-known example is Macromedia's Flash player. |
| PNG |
Portable Network Graphics - A popular image format for non-photographic images. PNG uses lossless compression and supports 16-bit colour (allows approx 65,000 different colours per image) and variable transparency. PNG is rapidly taking over from the old and defunct GIF format. The advantages of PNG are its support for a decent palette of colours, progressive display (you can see the picture build up before the whole image has finished Downloading) and its generally smaller file sizes. Some old Browsers cannot display PNGs, but all modern graphical browsers can. The RS infotech site uses only PNG and JPEG graphics. See also BMP. |
| POP3 |
Post Office Protocol version 3 - This is a standard mechanism for collecting E-mail, used by individuals or organisations who do not have their own e-mail server. Each e-mail address has a "mailbox" on the POP3 server. Effectively this is a storage area where e-mails are stored until the user is ready to collect them, just like a numbered Post Office Box, hence the name. Normally it is possible to connect to your POP3 mailbox from any suitably-configured E-mail Client on any Internet-connected computer. However, if you are a teacher in an LGfL-connected school and you want to check your personal POP3 e-mail then you're out of luck, because the over-zealous Firewall blocks POP3 access, among other things. Worse still, it works both ways, so you can't connect to your LancsNGfL-based mailbox from home either. Use WebMail instead, like all the children do ! |
| Port |
In general computer parlance, a port is a way in or out of a computer, for example a "printer port". Ports often equate to physical sockets, e.g. "mouse port". In Internet speak, i.e. TCP/IP networking, port has a very specific meaning. Using the analogy of delivering packets of information from one computer to another, each packet has to be delivered to the right "door" of a specific "building", but the IP Address only equates to a building; the "port" says whether the packet should go to the front door, tradesmen's entrance or the fire escape. Ports are the currency of Firewalls; a firewall in this analogy would be the firm of bouncers employed by the building. In technical terms, a port is a numbered subdivision of an IP address, and is represented by a colon and a number suffixed to the URL, e.g. http://www.rs-infotech.com:80 is the HTTP port on our Web Server. It is not necessary to specify the :80 because Browsers automatically add the prefix http:// if you type in an address without a Protocol prefix, and port 80 is assumed when the URL begins with the protocol http://. |
| Portal |
A Web Site that acts as a central access point for a related set of services, particularly in business-to-business areas. When the concept of "portals" first appeared, many were thinly-disguised shopping centres rather than being genuinely useful or objective, much as Web Directories tend to be now. |
| Post |
Various meanings all connected with sending a message of some sort. Also something that fences attach to. |
| PPP |
Point-to-Point Protocol - The Protocol that dial-up Modems use when they connect to an ISP. |
| PPPoA |
PPP over ATM - The Protocol that UK ADSL Modems use when they connect to an ISP. |
| PPPoE |
PPP over Ethernet - The Protocol that some Broadband systems use. Not used for standard ADSL in the UK. |
| Print Server |
Usually refers to a little box which allows one or more printers to connect to a Network. This means that the printer can be used by lots of people rather than just the person nearest the printer. We recommend that schools should have all their printers connected to print servers rather than connected to individual PCs. Even better, most heavy-duty printers are available in a "network" version, which means they have a built-in print server and often a built-in Web Server as well so that their control panel can be displayed in a Browser. |
| Private Key |
An essential part of most Encryption methodologies, specifically "PKI" systems such as the very successful PGP system. The private key, as the name suggests, is the bit that has to be kept secure because it enables the holder to decrypt (or sign) messages sent to (or from) the owner. In PGP, the private key can be very long and it is itself encrypted and needs a much shorter, usually memorised, "pass phrase" to unlock it. |
| Protocol |
Communication Language. Protocols are the various strictly-defined sequences of requests and responses that computers use to communicate with each other. Protocols usually have acronyms that end in "P", for example HTTP and SMTP. |
| Proxy Server |
In Internet usage, a proxy server is a "man-in-the-middle" between your Browser and the big, bad (slow) Internet. The proxy server gets its name because it fetches Web Pages from Web Servers on your behalf (like voting by proxy), so that your browser never directly communicates with computers on the Internet. The main feature of a proxy server is that it temporarily stores a copy of whatever page you were looking at, which means that if someone else wants to look at the same page (or has already looked at it), the second user doesn't have to wait as long because the proxy server already has a copy in its "Cache". Better still, clever proxy servers will attempt to anticipate your next move and will pre-fetch pages in advance so that you think that the Internet is really quick. On the other hand an overloaded proxy server can be a real bottleneck, making the Internet seem really slow, which schools may experience from time to time. Proxy servers perform other functions, one of which is to record all the Internet Traffic between an organisation's internal Network and the Internet, enabling management to see what the Internet is being used for. A proxy server may also be combined with a Firewall. |
| Public Key |
The publicly-published counterpart to the Private Key in "PKI" Encryption methodologies such as PGP. Anyone can use a public key to encrypt (scramble) a message intended for the key's owner. However, only the holder of the private key can unscramble the message. The main caveat with the PKI system is that you need to be sure that the public key you are using actually belongs to the person you think it does - i.e. it you must get it directly from that person or from a trusted source. RS infotech's public key is published on its Web Site, but you can save all the bother by using our "Contact Us" form - it automatically uses encryption. |
