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Mini-Glossary

 

Mini-Glossary

Browser:
A browser is a program that you run to view web sites or other pages written in HTML (Hyper Text Markup Language). The 2 most common are Netscape Navigator/Communicator and Microsoft's Internet Explorer. There are others but those are the most popular. If you're using anything older than Netscape 4.x or IE 4.0, you should download the newest version to be sure you can fully utilize all of the features on state_of_the_art web sites.

Internet:
The internet is a flexible system of servers and routers interconnected by telephone lines, fiber optic lines, satellite and microwave relay systems. It has been around much longer than it's been popular. Scientists and the military were the initial users but it's popularity has greatly increased with the advent of affordable personal computers.

Routers (general):
Routers help control the transfer of information at any hub on the internet. When accessing information, it's broken up into many different packets. All of the packets from a source may not follow the same path. The router keeps track of the packets, determines their path and helps to make sure the information reaches its destination.

Routers (home networking):
Home network routers isolate your home network from internet traffic. They are commonly known as NAT routers. Network Address Translation routers assign unique local IP addresses to the computers on the home network. If any of the computers on the home network check their IP address from a web site (type what is my IP in the address bar of your browser or seach engine), they will all appear to be the same computer because the servers for the web site will see the router, not the individual computers. Having the home network computers isolated from the internet helps prevent malicious access to those computers.

Servers:
A server may be nothing more than a standard personal computer or it could be a huge bank of supercomputers. If you have a computer that's accessible by others through the internet, you have a server. Most small dedicated servers are likely to have multiple processors and hard drives in a single case.

Intranet:
An intranet is a local network that may or may not be connected to the internet. Its main purpose is to share information for a small business.

ASP:
ASPs can also be active server pages. These are dynamically created pages instead of the more common static pages (with content that will never change until someone edits it).

ISP:
An ISP is an Internet Service Provider. They give you a path to connect to the internet.

Server Space:
Many times, when you sign up for internet service, the ISP will give you some space (usually ~1-20 megabytes of space) on their server. This allows you to put up a homepage with no extra cost for server space.

Downloading:
When you go to a web site, you're downloading information from the server where the web page resides to your computer. More commonly, it refers to copying information (software, music...) from an internet server to your computer.

Uploading:
Uploading is the opposite of downloading (duh!) and is generally done when you upload your website information to a server. Generally it's done with software that uses the FTP (file transfer protocol) rather than the standard HTTP (hyper text transfer protocol).

Bits:
A bit is essentially a single digit which, because it's used in the binary system, has only 2 possible values... zero and one. All of the information used by computers is transferred in bits.

This is a bit with a value of zero: 0
This is a bit with a value of one: 1

This is a 16 bit binary number with a value of zero: 0000000000000000
This is a 16 bit binary number with a value of 65,535: 1111111111111111

This is a 24 bit binary number with a value of zero: 000000000000000000000000
This is a 24 bit binary number with a value of 16,777,215: 111111111111111111111111

This is a 32 bit binary number with a value of zero: 00000000000000000000000000000000
This is a 32 bit binary number with a value of 4,294,967,295: 11111111111111111111111111111111

Bytes:
Since a single digit which has only 2 values is only marginally useful, they are grouped into groups of a predetermined size. A string of 8 bits is a 'byte'. A byte can vary in value from 0 to 255 which give it 256 possible values.

A byte with a value of zero looks like this: 00000000
A byte with a value of 255 looks like this: 11111111

Transfer Rates:
When you see something that indicates a file size or a rate of data transfer, it may be given in bits or bytes. Generally the value is high enough so that a prefix is required. Small files might kilo which means 1000. Larger files use the prefix Mega. Most of the time, the value is abbreviated so you'll see something like kb or Mb. You should notice that the 'b' in the 2 abbreviations was a lower case b. This denotes bits. If the b was upper case, it would indicate bytes. bits are generally used to indicate transfer rates for modems and such. Bytes are used when expressing file size.

One more note...
You'll notice that I used an upper case 'M' in Mb. The upper case M indicates mega or million. A lower case 'm' would indicate milli which indicates 1/1000. It would not be used in front of bits or bytes but you should know to use the proper case when dealing with prefixes.

Search Engines:
As you probably already know, Search engines help you find what you're looking for on the web. There are a few other things you should know. Search engines work in different ways. Some search engines have 'robots' that go out and look for new sites. Others rely on people to submit a site. There's still another type that searches only the meta tags on your site. Some search engines even search multiple search engines at a time.

USENET:
Usenet is the network of newsgroups.

Newsgroups:
Newsgroups are like bulletin boards where people can post messages or questions for a specific topic and those who are knowledgeable in the subject will try to help by posting responses. The information isn't always accurate but if you have several similar answers, you'll likely have the answer you need. If you want clarification, you can always post a more specific question. You should keep in mind that these groups are not always friendly and there's generally at least one person who's really confrontational and detracts from the group. There are other groups where there are many helpful people. I'd suggest reading the group for at least a couple of days to understand the 'tone' of the group. The best way to get quality answers is to post well thought out questions and use proper grammar and spelling. If they can't understand what you want, they won't bother helping. Since these are not chat rooms, it may take a day or more to get any responses.

Signature File:
A sig file is a text file that's attached to your email messages and newsgroup posts. It generally looks something like this (including the tildes - the squiggly things):

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'your name'
'your site address'
'A small clever quote or information about you or your site'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Pixels:
Pixels are 'picture elements'. In computer graphics, they are the little dots that make up an image.

Bitmap Images:
Bitmap images used on web pages include .jpg and .gif files. There are other bitmap formats (.bmp, .tif...) but they're not used in web pages. A bitmap file contains all of the information for each pixel in the image. A bitmap image works well if used at the same size as it was drawn but quickly looses quality if it's enlarged or stretched.

Vector Images:
Vector image files use lines, curves and fills to construct or reconstruct an image. The file sizes are generally smaller than bitmap images and can be scaled infinitely without a loss of resolution. These files can not be used directly in web pages. Macromedia's 'Flash' software allows the vector images to be used in web pages. Many graphics programs such as Corel Draw and Adobe Illustrator use vectors.

Animated GIF:
An animated gif file is a group of individual gif images that are played in sequence.

Flash:
Macromedia Flash© is a software package used to create dynamic content on web sites.

Midi files:
Midi (Musical Instrument Digital Interface) files are often used on web sites due to their small file size. These files generally lack realism but allow you to use background music on your site.

WAV files:
Wav Files are raw data files that have information that's sampled a specific number of times per second. Standard digital audio such as that found on CDs is sampled at 44,100 times per second. This allows a frequency response of up to ~20,000 hertz. Lower sampling rates allow smaller data files but will also reduce the maximum reproducible frequency. The maximum reproducible frequency is half of the sampling frequency. These files can be used on a web site but the download time can be quite long if the file is of high quality.

MP3 files:
Layer 3 mpeg files (MP3 files) are the third version of mpeg encoding. It is a compression scheme that results in files that are significantly smaller than comparable wav files. It can produce audio files with little or no loss in sound quality. The actual sound quality can be as good as CD quality (with a ~12:1 file compression ratio) for files encoded at a bit rate of 128kbps (thousand bits per second) or as low as telephone quality (a ~96:1 file compression ratio) when encoded at 8kbps. For more information on MP3s, including software and hardware, go to MP3.com.

Screen Resolution:
The screen resolution expresses how many pixels are displayed on the monitor. If your computer's resolution is set to 800x600 and you're looking at a picture whos dimensions are 800x600 pixels, the picture will fill the entire screen. If you set the resolution to 1280x1024 pixels (probably the most common setting), the 800x600 picture will appear smaller than it did at the lower resolution. You would also notice that the icons on your desktop would be smaller at 1280x1024 (because they're image on the screen is a fixed number of pixels). At higher resolutions (1920x1080), you may need a relatively large monitor to get acceptable size buttons and icons on the screen. With older CRT monitors (large, heavy, glass screen...), the resolution wasn't really important because all resolutions had roughly the same quality. With LCD monitors, this isn't the case. LCD monitors have a 'native' resolution. If they're not used at that resolution, the image quality will be far lower than if it's used at it's native resolution.

Color Depth:
The color depth will determine how many colors your computer will be able to produce. At one time, computers didn't have enough power to produce many colors. Actually, there was only 1 color (green on a black background). As computer technology advanced, they were able to display more and more colors. The minimum acceptable color depth is 256 colors (8 bit color) and it's not good if you are going to deal with graphics such as photos. Most people use at least 16 bit color which translates into 65,536 colors. Most computers can go to 32 bit color. 24bit color gives 16,000,000+ colors. 32bit color has the same colors as 24 bit but it has an 8 bit alpha channel. The alpha channel handles transparency effects.

Hard Drive:
A hard drive is where your files are stored in your computer. It is made up of multiple hard discs coated with a magnetic storage medium (very roughly similar to what's on a cassette tape). It has magnetic read/write heads for each of the discs. These heads can travel the width of the magnetic media on each disc. The discs are spun at a high rate of speed (4,200-15,000 RPMs depending on the drive) and the heads move across the disc where they either read data or write data. Most modern hard drives can hold at least 20 gigabytes (20,000 megabytes) of data. Some of the newer hard drives are as large as 1,000 gigabytes. Your requirements for hard drive space will largely be determined by the types of files that you'll need to store. If you're going to have a lot of image files (jpg, gif...), audio files (wav, MP3) or video files, you'll need a larger hard drive than if you were only going to check email and write text files.

Solid State Drive (SSD):
The SSD serves the same purpose as a hard drive but they're faster, (generally) smaller and use less power than standard (spinning platter) hard drives. The downside is that they're (currently) more expensive than standard drives when you compare the storage capacity.

CPU:
The CPU (central processor unit) the the computer's 'engine'. It determines how fast the computer can make calculations. It is, however, not the only thing that determines how fast a computer can respond to commands.

Mother Board:
The mother board is the large main board in your computer. It provides the data connections for all of the other boards and many of the internal drives in your computer. The CPU is mounted on the motherboard.

Daughter Board:
A daughter board is a small board that plugs into the mother board. Some of the older computers had the CPU and the associated components (memory, cache...) mounted on a daughter board which plugged into the motherboard.

Modem:
The modem is the component which transfers the data from the computer's mother board to the telephone (or cable) lines. It's speed (33.6kbps, 56kbps...) determines how fast the information can be transferred from the net to your computer. The higher numbers will relate into higher transfer rates. Although some people still used 'dial-up' modems, most people are moving towards broadband connections (DSL, cable). Broadband is faster and you don't have to wait for the modem to dial in to the internet service provider.

Discrete Expansion Cards:
Many motherboards have integrated video, sound and ethernet controllers/processors. If these are not performing as well as you need, you can add 'discrete' cards in the expansion slots on the motherboard.

Video Card:
Video cards convert the data from the computer's processor into information that can be used by your monitor. All video cards come with memory. In general, more memory will allow higher screen resolutions at higher color depth. The GPU (graphics processor unit) determines how fast the video card can process the video. High performance video cards come with very fast processors and lots of memory.

Sound Card:
The sound card is where you connect your peripheral audio equipment. Most sound cards have external connections for microphone input, line input and line output. Many of the new cards (even those integrated into a motherboard) can produce 5.1 surround sound.

USB Port:
A USB (universal serial bus) port allows many different types of peripherals to be connected to your computer. Digital cameras, modems, printers, scanners and drives (just to name a few) use USB ports. USB 2.0 ports can transfer data at rates at up to 480mbps. USB is significantly faster but not as well supported (fewer motherboards have USB 3.0 interface connections).

Serial Port:
The serial port can be either a 9 pin or 25 pin connector (these are being phased out). The data transfer in either is the same. This type of connector is used to connect to your mouse or external modem.

Parallel Port:
The parallel port on the back of your computer can transfer data on 8 pins at a time which makes it able to transfer data faster than a standard serial port. The connector is a 25 contact connector which has 25 sockets to accept the 25 pins on the interconnect cable. This is the port you might use for your printer (if you have an older printer).

CD-ROM Drive:
A CD-ROM (read only memory) is a drive which accepts a standard CD containing either data or audio. Some are equipped with a mini headphone jack and a volume control on their front panel for listening to audio. They also have an internal audio connector which connects to your computer's sound card. Data discs can hold 700 megabytes of information.

CD Burner:
A CD 'burner' drive has a special high powered laser that can 'burn' information onto special CDs. It's used to make and read data or music CDs.

CD-R/CD-RW:
Both CD-R and CR-RW can be written with a CD 'burner'. A CD-R can only be written once. A CD-RW can be written and rewritten many times. CD-R audio discs can be read by CD ROM and audio CD players. CD-RW drives can generally only be read by CD-RW drives.

DVD-ROM:
DVD-ROMS are a relatively new format that is completely different from the other CD formats I mentioned (except for the size of the disc). The information can be on a single layer, 2 layers, or if it's a double sided disc, 4 layers. It can store much more info than a standard CD ROM. As much as 17 gigabytes if all 4 layers are used. Blank DVDs are available in DVD5 (4.7GB) and DVD9 (8.5GB). At this time, double-sided blanks are not available.

Floppy Disc Drive:
The most common floppy drive uses 3 1/2" discs. The original 'floppy' discs were 5 1/4" discs and were actually floppy. The 3 1/2" 'floppy' discs are in a hard plastic casing and are no longer floppy. The discs can hold ~1.44 megabytes of data. These are rarely used now.

Zip Drive:
A Zip drive is a drive made by Iomega. It can store between 100MB and 750 megabytes of information on a removable disc. It is useful for transferring large files from one computer to another. These have

Switching Power Supply:
A 'switching' power supply is a power supply that performs the required voltage conversion through high frequency switching. It switches the voltage on and off at a rate of 20,000 times per second to 1000,000 times per second. The percentage of on/off determines the output voltage when the power supply is regulated. When the power supply uses a variable pulse width (different percentages of on/off) to perform the regulation, it's called a PWM (pulse width modulated) power supply. Switching power supplies are more complex than linear power supplies but they are much more efficient.

Computer Power Supply:
The computer's power supply is a switching power supply that converts 120 volts AC to 3.3 volts DC ±12 volts DC and ±5 volts DC. These voltages are needed by the various systems in the computer.

 

 
 
 
 
 
 

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Perry Babin 2005 - Present
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