The smallest amount of information stored on a computer or transmitted via telecommunications is the bit. A bit is either "on" or "off" in the form of a 0 (zero) or 1 (one).

Eight bits make a byte. A byte is the combinations of bits in patterns that represent alpha-numerical characters, A-Z and 0-9. Bits and bytes represent units of memory storage for a computer. Memory increases are measured in increments of the powers of 2: 2 to the tenth power (a kilobyte), 2 to the twentieth power (a megabyte), etc.

Computers have drives:

• hard drives measured in GB's (250GB3 Serial ATA Hard Drive (7200RPM) w/DataBurst Cache™)
• RAM was measured in MB's; 16 - 128MB's or more (2GB Dual Channel DDR3 SDRAM 1333MHz - 2DIMMs)
• 3.5" floppy measured K's; (Note: double-density = 720K; High-density = 1.44MB)
• zip drives measured at 100 MB's or 250 MB's
• DVD drives DL DVD (9.5 GB) ; Dual Layer Blu-ray Disc (50GB)
  http://www.dell.com/content/learnmore/learnmore.aspx?c=us&l=en&s=gen&~id=hmc_optical_vostrodt&~lt=popup
• other drives

Dell Vostro 430 Desktop Mini Tower

The following table allows you to compare the size of the information packages that you might want to send, recieve or store via the Internet.

Bits and bytes represent units of memory for computer storage. They also represent data flow capacity called bandwidth. Bandwidth represents the amount of data that can be transmitted from one location to another in a given amount of time. Bandwidth in generally expressed as the amount of data that can be transferred in one second.

Bandwidth is similar to pipelines. Generally, the larger the pipe, more data can flow faster. Some pipes are like hoses that can only feed data so fast and are only 1 inch in diameter. This would be a 56K modem. Other pipes are like 6 foot diameter sewer pipes where lots of data can flow with almost no speed limit. This would be a T3 line.To improve bandwidth we look for faster/bigger connections. This is acheived through improvement in telecommunications devices and physical connection lines. (more on this later in the section on connections)

When Internet data has to flow in "real time", such as streaming audio or video, very high bandwidth is required to allow it to run without perceptible delays, stuttering or interruptions.

What I would assume is a common misconception, is that the bandwidth between any two devices is automatically saturated upon connection (i.e. file transfer) between devices. In actuality many other factors exist that would detriment the actual throughput between devices. A perfect example being my internet connection; I have Comcast cable (16Mbit) yet when I download a file I will rarely saturate my connection, due to the multiple other factors that affect file transfer speed.

    A quick note, download speed as commonly reported by web browsers is displayed in either kiloBYTEs per second (kb/s or kbps) or megaBYTEs per second (mb/s or mbps) whereas my connection speed is measured in megaBITs per second. So a file downloading at 300 kbytes/s can also be measured as a rate of 2400 kbits/s or 2.4 mbits/s because a single byte is composed of 8 bits (more often than not). Following up on the previous paragraph, to calculate the max file download speed for my internet connection, we’d just divide my maximum bitrate by eight, thus {(16mbit/s) / (8) = (2mbyte/s)}. So my maximum download rate would be 2000 kbyte/s or 2 mbyte/s.

Bandwidth Bottlenecks

Most of the Internet backbone runs on very high bandwidth connections like T1 lines or faster. However, your connection (the on-ramp for sending, the off-ramp for recieving information) generally is the bottleneck for communications speed. Even if a 5 MB file moves from server to server and routes from Washington D.C. to Snata Cruz, CA in fractions of a second over high bandwidth Internet backbone connections, if you have a 28K modem it hits the brakes on the off-ramp to your computer and slows to 28,000 bits/second.

Telecommunications - the communications infrastructure that carries information to and from the Internet. There are four key technologies for transmitting data:

1. Traditional telecommunications using compression software and faster switches are developing new technology for higher bandwidth communication using existing networks (phone lines, DSL, ISDN, fiber optic, fax, etc.) example: Cruzio http://gate.cruzio.com/
2. Satellite Technology vendors giving us global reach with broadband networks give access to non-phone service areas (copper wire not available). It will be much faster at a lower price in the future making network access available to all.
   http://www.starband.com/
   http://www.direcpc.com/
3. Wireless network providers will give households and buildings wireless connectivity for all devices via Internet protocols. Wireless phones not only receive and transmit voice, video and other data but now can process it as well.
   Wi-Fi http://www.webopedia.com/TERM/W/Wi_Fi.html
   
   Phone dial up + ISP (i.e.: T-Mobile + Netzero)
   http://www.t-mobile.com/
   http://www.t-mobile.com/shop/plans/default.aspx?plancategory=7
   
   http://www.cellularone.com/Home1.asp
4. Cable companies, using the same cable system for more than television, provide two-way data communications using set-top boxes that act as converters and separators for audio, video and other data inbound and outbound. Example AT&T http://www.attbroadband.com/services/
   http://www.comcast.com/

Most users (client computers) are connected by modem through telephone lines to an ISP (Internet Service Provider) that is our on-ramp/off-ramp to the Internet. This is called a dial-up connection. Modem is short for modulation-demodulation, wherein modulation converts a digital signal to analog for transmission throught he phone lines and demodulation converts the signal back to digital. Modems must be turned on and use your telephone line, often preventing you from having use of your telephone while connected unless you have multiple phone lines in your home.

Other connections are always-on connections (DSL, ISDN, CABLE, T1, T3, ATM) using other types of wire or fiberoptics. Additionally, radio and satellite wireless connections are common.

Other ways to connect involve wireless radio wave (cell phone technology) connections or connecting through an Intranet's connection such as your intranet at work. Cabrillo uses Calren, who provides our network. This is done through SBC and a very large cabinet in the basement of the 100 building. We have a DS3 connection with potential to add several times the capacity.
http://www.cenic.org/CalREN/

ISP Connection Options Costs and Speed

ISP's generally offer Internet connectivity AND other services to customers such as you and me: email, ftp, domain hosting, etc. The backbone of the Internet is connected by large ISP's sometimes called IAP's or Internet Access Providers. IAP's don't deal with individuals or small businesses. Network Access Providers, NAP's, are at the top. They are the domain registrars and large, core Internet organizations that regulate and run the Internet.

Cabrillo College Connectivity: Calren is who provides our network. This is done through SBC and a very large cabinet in the basement of the 100 building. We have a DS3 connection with potential to add several times the capacity.
http://www.cenic.org/CalREN/

The Web servers and ISP connections might follow a hierarchy similar to the figure below.

Most people choose an ISP that is local. Local ISP's usually offer full ranges of service including email, chat, newsgroups, ftp, free web space and domain hosting, workshops and much more. They may offer a variety of connectivity options or just a few. Some will offer eCommerce solution software and secure server domain hosting and assist with setting up domain name registration and pay systems. Most offer dial up and always on connection options. Some of Santa Cruz local ISP are:

There are many national and international services to choose from as well. Most have many local dial-up numbers so that you have access without long distance charges as you travel. Most do not offer connectivity that is not dial up. Some well know choices include: