Glossary
F
FAQ. An Acronym for Frequently Asked Questions. USENET
newsgroups use this moniker. Oftentimes people ask the same questions
over and over. To satisfy them without repeating a lot of information,
the questions and answers are put into either a FAQ file or a FAQ area
of the newsgroup.
FAT. A DOS acronym for File Allocation Table, which is
a special part of every disk that stores sizes and locations for all the
files saved on the disk.
FCC. Abbreviation of Federal Communications Commission.
Among other duties, the FCC is responsible for rating personal computers
and other equipment as either Class A or Class B. The ratings indicate
how much radiation a personal computer emits. Almost all personal computers
satisfy Class A requirements, which means they are suitable for office
use. Class B machines, which are suitable for use anywhere (including
the home), must pass more stringent tests. Class B indicates that the
machine's radio frequency (RF) emissions are so low that they do not interfere
with other devices such as radios and TVs.
fiber optics. Thin strands of glass used to carry light signals
for communication purposes. A tiny strand of fiber optic cable can replace
huge copper cables. Not only do fiber optics take up less space, but they
can carry more information as well. Fiber optics are very popular for
modern LANs because they are less susceptible to radioactivity and other
types of interference.
field. One complete vertical scan of the picture, containing 262.5
lines. Two fields make up a complete television frame; the lines of field
2 are vertically interlaced with field 2 for 525 lines of resolution in
the NTSC standard.
FIFO. Acronym for First In, First Out. A term used by programmers
to describe a data structure called a queue where the first item
stored is also the first item retrieved.
file. A collection of information stored on a disk, and accessible
using a name.
file attribute. Information that defines the characteristics of
a file. Some characteristics of a file may be hidden, read-only, locked,
or archive. Changing a file's attributes does not affect the file's contents
but does affect the computer's ability to modify or view the file.
file compression. The smashing (or squeezing) of a file into something
smaller so that it takes up less disk space (or takes less time to transmit).
file conversion. The translation of one file format (file structure)
into another one.
file server. A network computer that stores all of the users'
programs and data files on its own hard disk. Most large networks have
at least one file server. File servers are particularly useful for acting
as post offices for electronic mail messages or other applications where
users need to share files or send them back and forth. Because the file
server spends its time running the network, nobody can use the file server
computer to do anything else.
file sharing. The ability of a network computer to share files
or directories on its local disks with remote computers.
file size. The amount of disk space that a file requires for its
existence, usually measured in bytes.
File system. In an operating system, the overall structure in
which files are named, stored, and organized.
Finder. The part of the Apple Macintosh operating system that
provides cute little icons, menus, and windows for copying, moving, and
deleting files.
firmware. Software embedded into a chip as opposed to being stored
on disk and loaded into memory.
fixed disk. Another name for a hard disk. You can't remove the
disk from the computer, hence the name fixed.
fixed wireless. Fixed wireless refers to wireless devices or systems
that are situated in fixed locations, such as an office or home, as opposed
to devices that are mobile, such as cell phones and PDAs. Fixed wireless
devices normally derive their electrical power from utility mains, as
opposed to portable wireless devices that normally derive their power
from batteries.
The point-to-point signal transmissions occur through the air over a terrestrial
microwave platform rather than through copper or fiber cables; therefore,
fixed wireless does not require satellite feeds or local phone service.
The advantages of fixed wireless include the ability to connect with users
in remote areas without the need for laying new cables and the capacity
for broad bandwidth that is not impeded by fiber or cable capacities.
flatbed scanner. A device that lets you lay full-size (8.5"
x 11") paper face-down on its surface to be electronically "read."
floppy disk. A magnetically coated disk you use to store information
for a computer.
folder. Another name for a subdirectory.
footer. A short title, word, or phrase that appears at the bottom
of a page in word processors or desktop publishing programs.
format. To prepare a floppy or hard disk for storing information
for a specific type of computer. A floppy disk can be sued by any type
of computer. Formatting a disk on a Macintosh prepares that disk for storing
Macintosh data. Formatting a disk on a DOS machine prepares that disk
for storing IBM-compatible data.
frame. A rectangular area used by word processors and desktop
publishing programs for arranging text or graphics on a page.
frame relay. A packet-switching protocol for connecting devices
on a Wide Area Network (WAN). Frame Relay networks in the U.S. support
data transfer rates at T-1 (1.544 Mbps) and T-3 (45 Mbps) speeds. In fact,
you can think of Frame Relay as a way of utilizing existing T-1 and T-3
lines owned by a service provider. Most telephone companies now provide
Frame Relay service for customers who want connections at 56 Kbps to T-1
speeds. (In Europe, Frame Relay speeds vary from 64 Kbps to 2 Mbps.
In the U.S., Frame Relay is quite
popular because it is relatively inexpensive. However, it is being replaced
in some areas by faster technologies, such as ATM.
freeware. Software that's copyrighted but allowed to be copied
and give away freely without cost. In comparison, public domain software
is not copyrighted and can be copied freely, and shareware is copyrighted
and can be copied freely but must be paid for if used regularly.
Fresnel Zone. (pronounced 'fre-nel' the "s" is silent)
The area around the visual line-of-sight that radio waves spread out into
after they leave the antenna. This area must be clear or else signal strength
will weaken. Fresnel Zone is an area of concern for 2.4 GHz wireless systems.
Although 2.4 GHz signals pass rather well through walls, they have a tough
time passing through trees. The main difference is the water content in
each. Walls are very dry; trees contain high levels of moisture. Radio
waves in the 2.4 GHz bank absorb into water quite well This is why microwaves
-- which also use the 2.4 GHz bank -- cook food. Water absorbs the waves,
and heart from the energy cooks the food.
FTP. File Transfer Protocol. The standard method of transferring
files using TCP/IP. FTP allows you to transfer files between dissimilar
computers, with preservation of binary data and optional translation of
text file formats.
full duplex. The simultaneous transmission of data in both directions,
used when communicating between two computers. Full duplex is sometimes
called Echo On by some communications programs.
full pathname. The name of a file plus the drive and directory
where the file is located. Examples of a full pathname are C:\WINDOWS\SYSTEM\WIN.INI
and D:\UTIL\ZIP\PKZIP.EXE.
function. Like a subroutine, functions allow you to assemble a
series of commands together. Functions may then be invoked from anywhere
else within a program. Functions are identified by names and often read
parameters. However, functions also return a resulting value.
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