Information Technology Flashcards
Open Source Principles
Free distribution and redistribution, source code availability, provisions for derived works
Examples of Open Source
Linux, OpenOffice, GIMP, Mozilla, Apache, MySQL
Examples of Proprietary
Windows, Microsoft Office, Photoshop, Internet Explorer, IIS, Oracle
3 Open Source Tech. major to internet
Linux, Apache, MySQL
Pros - open source
peer-reviewed code, dynamic community, rapid bug fixes, released by engineers
Cons -open source
dead-end software, fragmentation, developed by engineers, inability to point fingers
Open Source in LIS
used very frequently
Omeka
Omeka is a free, flexible, and open source web-publishing platform for the display of library, museum, archives, and scholarly collections and exhibitions.
Nvivo2.0
Nvivo is a QSR software that supports qualitative analysis. Using Nvivo facilitates content analysis and the search for frequencies and co-occurrences of codes and attributes.
Telecommunications
Electronic transmission of signals for communications
Telecommunications medium
material substance that carries an electronic signal to support communications between a sending and receiving device
synchronous communications
receiver gets message instantaneously
asynchronous communications
receiver gets message after some delay
simplex channel
transmits data in only one direction
half-duplex channel
transmits data in either direction but not simultaneously
full-duplex channel
permits data transmission in both directions at the same time
channel bandwidth
rate at which data is exchanged, measured in bits/sec
circuit switching network
sets up a circuit between the sender and receiver before any communications can occur
packet switching network
no fixed path is created between the communicating devices,
telecommunications media categories
guided transmission media and wireless
guided transmission media trypes
twisted pair wire, coaxial cable, fiber-optic cable
twisted-pair wire
classified by cateforey
coaxial cable
offers cleaner and crisper data transmission (less noise) than twisted-pair wire
fiber-optic cable
transmits signals with light beams
wireless transmission
broadcast of communications in one of three frequency ranges
personal area network
support interconnection of information technology within a range of about 33 feet (bluetooth)
local area network (LAN)
connect computer systems and devices within a small area, e.g., office or home
metropolitan area network (MAN)
connect users and their devices in a geographical area that spans a campus or city
wide area network
connect large geographic areas
ethernet
main technology for local area networks, used for connecting all computers in a lab
channel
wire that = physical setup for an Ethernet network
router
variation of a LAN connection, physically connected to an ISP’s modem, connected to the Internet, Capable of broadcasting and receiving signals
client
any computer that sends messages requesting services from the servers on the network
server
provider of a resource or service, e.g web server, printer, etc
the internet
made up of computers, network hardware, fiber-optic cables, software, and the TCP/IP protocols
point-to-point asynchronous communication
fast enough to mimic synchronous communication
ARPANET
ancestor of the internet, project started by the DOD in 1969
Backbone
Internet’s high-speed, long distance communication links
Internet Protocol (IP)
Enables computers to route communications traffic from one network to anouther
Transmission Control Protocol (TCP)
Transport-layer protocol that most Internet applications use with IP
Uniform Resource Locator (URL)
an assigned address on the Internet for each computer
IP Address
A unique address, series of four numbers (one byte each), range of each of these numbers (0-255) allows for billions of IP addresses
top-level domain
.edu, .com, .org, .net, .mil, .gov
Ping
allows us to see if a computer on the network is available
trace route
displayes the route and transit delays of packets across an internet protocol
ISP
individual connections to internet via internet service provider
Enterprise network
larger network organization that connects to the Internet by a gateway
peering
two or more autonomous networks interconnect directly to exchange traffic (free)
transit
allowing network traffic to cross a computer network
cellular wide area network
base stations serve cells, land area served by cell towers
Wi-Fi
simply connecting to a Wi-Fi router in your home
“The Web”
consists of server and client software, the Hypertext Transfer Protocal (http), standards, mark-up languages that combine to deliver information and services over the Internet
Hypertext Transfer Protocol (HTTP)
a communication standard governing the requests and responses that take place between the web browser running on the end user’s computer and the webserver
Three Parts of URL
Protocol, Server Computer’s name, Page’s pathname
URL Protcol
Tells computers how to handle the file
Server computer’s name
name given by the domain hierarchy
Page’s pathname
Tells server which file (page) is requested and where to find ti