This long promised glossary is not alphabetical since that doesn't work very well for this type of material. It is loosely organized in some logical groupings but it is short enough that the best approach is just to skim the words in the left column to find ones you've heard and wondered about. Often it seems like you are the only one in the room that doesn't know what the "cloud" is but you are not alone. Here's your chance to catch up and get ahead of most of the people you encounter.
Word
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Definition
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Mobile Devices
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Smartphones and Tablets are the most
talked about mobile devices today. In a word, they are computers that are
portable in the extreme. They have processors, memory, operating systems,
keyboards and touchscreens for data entry and for displaying the output. Most
importantly, to qualify as general-purpose computers they allow user
installation of programs (apps in today’s vernacular). Without this last
requirement some current refrigerators – and future toasters – would likely
qualify as general-purpose computers.
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Tablet
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Tablets
are at the large end in terms of mobile screen size – typically seven to ten
inch diagonal measurement. The other primary difference from smartphones is
that tablets generally don’t have a connection to a cell phone network and if
they do it’s not used for phone calls – just for Internet activities. There
is nothing stopping a company from putting a cell phone capability into a
tablet. Two reasons they probably won’t: the tablet war is turning into a
price war and every penny they can cut from the cost is a penny they can
keep; the idea of talking into a tablet just seems strange and most tablet
owners have or will have a cell phone. Nomenclature will be confusing for a
while since someone could – and probably will – put telephone circuitry into
a ten inch tablet or remove it from a four inch smartphone.
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Phone - Smartphone
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Smartphones allow users to install apps of their choosing
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Phone – Feature phone
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Feature phones can perform tasks using the Internet such as email and web surfing.
They come with a fixed set of apps – calendar, contact list, etc.
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Phone – Cell phone
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Simple cell phones are used only for making
phone calls.
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Cell phone contracts
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Many phones receive
service from one of the carriers (AT&T, Verizon, etc.) based on a
contract. Monthly charges are based on four elements.
1)
Number of
minutes of call time
2)
Number of text
messages
3)
Amount of
information sent and received (the dataplan)
4)
Fees and taxes
Dataplans
are likely to cause significant confusion in the future since we are using
mobile devices more frequently and very few people know how many megabytes
are in a video.
Traditional cell phones do
not require dataplans. Prepaid cellphones are traditional cell phones that
allow you to buy minutes in advance. These are individuals with limited need
for a cell phone.
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Internet TV
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Much of our television in
the future will come through the Internet. A simple computer can be
incorporated into a TV set or offered as a standalone box. No matter the
form, these are real computers – generally with limited storage. Content is
streamed from the Internet not stored locally. They use the TV as a display
and a remote control or keyboard for input. Some have relatively simple
choices while others offer a full web browser on the TV.
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App
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An app is just a new name for a program. You used to install
programs; now you install apps.
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Operating System - OS
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All computers including
desktops, laptops, smartphones and tablets have a program called the operating system (OS). In the past
the three best-known computer operating systems were Windows, Mac and Linux.
Currently the top mobile operating systems are Google’s Android and Apple’s
iOS. There are at least ten mobile operating systems today but few are likely
to survive very long.
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UI – User Interface
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Ever since Apple
introduced the graphical user
interface in 1984 (icons manipulated with a mouse on a “desktop”) the User Interface (UI) has been
critical. Methods of interacting with a computer (using a mouse and keyboard)
have progressed slowly in recent years but touchscreen technology is changing the UI at lightening speed.
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Wireless connections WiFi, Bluetooth, etc.
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All of these are just the
various types of radio signals that are used to connect devices wirelessly.
They’re called radio signals since they were used for radios decades before
computers were invented. For a more detailed explanation check out my July blog post.
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Cloud
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In the simplest terms the Cloud means storing information
and running problems on the Internet rather than your PC. For the
professionals it is much more complicated and you can read more in my June
2011 Newsletter.
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Internet and the World Wide Web (Web)
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The Internet consists of millions of computers connected together.
They may be gigantic machines but even your personal computer is an Internet
computer when it is online.
The World Wide Web consists of software and files that allow anyone
to use Internet computers to store and retrieve information - information
that might be text, photos, music, etc.
A web server is one of the most important web programs since it
sends files (web pages) to you when you click on a link or type an address
into your browser. It sends (or serves) the page to you and then waits
patiently in case you want another file – possibly serving thousands of files
to other users in the meantime.
Sending and retrieving web
files is only one use of the Internet. Email is another. Email uses the
Internet but not necessarily the web. This situation is somewhat confusing
since many email services are now available through your web browser.
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Protocol
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If two computers (or two
people) are going to work well together, they have to agree on how they will
do things. Often these agreements are called protocols. Who sits where at a state dinner is
determined by the protocol for state dinners. In the case of computers, how
they exchange information is called a protocol that is described first on
paper – which signals are going on which wires, etc. To be able to
communicate both computers must have a program that implements a particular
protocol. Basically it’s a description of what characters will travel between
the two computers and in what order. You may hear about IP addresses – these
are the addresses used by all computers on the Internet (even yours)
according to the Internet Protocol.
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Encryption
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We all remember making up
secret codes at a very young age. Encryption
is just the name for a myriad of techniques that can transform a message –
text, photo, etc. – so it cannot be understood if it falls into the wrong
hands. Breaking enemy codes was a major undertaking in World War II and today
any spy agency worth its salt is doing the same thing with information
intercepted on the Internet.
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Units – Bit, Byte and Megabyte
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We’ve heard that all
information in a computer is stored as zeros and ones. If you put enough
zeros and ones together you can represent a text book or reproduction of the
Mona Lisa. If you take an image from your digital camera or off the Internet
and enlarge it many, many times, you will see individual picture elements,
(pixels or dots). Each pixel is a single color and that color is represented
by a number – a string of zeros and ones.
Storage space for a single
zero or one is called a bit – just
like storage space for a number from 0-9 is referred to as a digit.
A group of eight zeros and
ones is referred to as a byte. As
a rough approximation a single character of text can be represented by a
combination of zeros and ones stored in one byte (a=00000001, b=00000010,
etc.)
A kilobyte is roughly one thousand bytes; a megabyte is roughly one
million bytes and a gigabyte is
roughly one billion bytes. I say roughly because there are two definitions
for each of those terms but they are similar enough for most people to
ignore.
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Pixel
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A pixel is a single point (dot) in an image. A ten megapixel camera
can take pictures with approximately ten million pixels. Each pixel requires
several bytes of memory to record the color – see pixel depth.
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Pixel depth
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Each pixel (dot in an
image) can represent millions of different colors. The value stored for each
pixel indicates the color of that dot. The higher the pixel depth (more bits
to store the value), the more colors that a pixel can represent. For example,
if you stored the color of a pixel as a two digit number, you could store up
to 100 different colors – 00-99. Computers store values in binary but the
principal is the same.
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Compression (JPEG or JPG for still pictures and
MPEG for videos) In practice there are many other compression standards.
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Storing a color value for
every pixel in an image results in very large files. It is common practice to
compress the image by, for example, indicating that a large area of sky is
blue with only a few values – the numeric value for blue color and the
boundaries of the block of sky. A tiny speck of a bird in the sky might just
be tossed out in the process. The higher the compression, the smaller the
resulting file and the more image points will be lost or modified.
Videos can have each
individual frame compressed in this way but add interframe compression; if
two successive frames are nearly identical, only the changed pixels are
included for the second frame.
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Broadband
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Generally used to describe
high speed Internet access with a variety of speeds. Usually contrasted with
dialup connections.
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Modem/Router
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The telephone system was
originally intended to transmit human voices. When we began sending
information between computers over phone lines, there had to be a way of
changing zeros and ones to sound patterns (called modulating) when they were
sent and then back into zeros and ones (demodulating) at the other end. The
device we use is a modulator/demodulator (modem) - one at each end of the line.
If there are multiple
computers in your home or office and only one Internet connection, you need a
way to keep transmissions separated. Signals from a computer connected a
wireless network go first to the router which attaches a numeric code to
indicate which computer sent it. When a response to that transmission is
received over the Internet it comes back through the modem and then to the
router to send it to the correct computer. Today modems and routers are
usually combined into a single device that does both jobs.
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HTML
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A file type indicates what type of program created or can read a
particular file - .doc for MS Word, .xls for Excel, etc. Files that come over
the Internet to be displayed by a browser like Internet Explorer, Firefox or
Safari use .html or .htm as a file type.
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Flash
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Flash is
a type of file often used for video but for other purposes as well. Flash is
losing favor as other more modern programming tools are developed, e.g. HTML
v5.
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PDF files
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The pdf file type was developed in response to the many incompatible
file types that were causing confusion. The idea was that all computers could
have a pdf file “reader” so any document – word processing, spreadsheet, etc.
– that could be converted to a pdf format could be read on any computer.
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URL
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A Uniform Resource Locator is the fancy name for the Internet
addressing scheme. You could type an address into your web browser and call
it either an address or URL. URL is the cooler term.
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Touchscreen
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Smartphones and tablet
computers use display screens that can detect the touch of a finger or
special soft stylus. They can be programmed to respond to various gestures –
tap and double tap, as well as sliding motions involving several fingers.
Cheaper touchscreens require pressure but later, higher quality screens
respond to a very light touch. Touch gestures often imitate mouse clicks –
double click/double tap, click and drag/tap and drag, etc.
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Domain Names
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To provide some structure
to Internet addressing, the scheme starts with Top Level Domains. These
include .com, .edu, .mil, .gov and .biz - called generic TLDs. They are not
associated with any country. TLDs also include two letter country codes .us,
. ca. ru, etc. New top level domains are just being rolled out now.
Any organization that
wants an Internet address can apply for its own name – braley.com or
braley.us – consisting of a specific name associated with one of the TLDs.
Needless to say most common words and proper names are already taken.
This is how requests for
information are routed around the Internet. Braley.com is essentially a
folder of files stored somewhere on the Internet. One of those files is the home page that will be retrieved if
no further information is provided. In most cases, someone might want a
specific file and request braley.com/clients.htm. This is a file in the
braley.com folder
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www, http, https, ftp
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A web file usually starts
with www (world wide web) but if
you leave that out, your browser will generally insert it for you. The
Internet operates on Hypertext Transport Protocol - http -but again the browser will often add that to an address.
Secure web sites use https and it
is important to put that in to access those sites. FTP is the file transfer protocol – not a web service – which at
one time required a separate – non-browser – program. But like many other
services, FTP can usually be handled by your web browser.
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Browser
|
A web browser was once a program with one purpose – to display
files ending in htm or html. These programs have been greatly expanded to
perform numerous other functions – see FTP above.
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Email and web capitalization
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Email addresses are NOT
case sensitive. Web addresses are NOT case sensitive up to the first slash
following the .com, .gov, .us, etc. Following that slash they may or may not
be case sensitive so you need to assume they are unless you know otherwise.
Braley.com is never case sensitive but the “file1.htm” in
Braley.com/file1.htm is likely case sensitive.
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