Chapter 2

Front 1

Application
Architecture

Back 1

the way in which the functions of the application layer software are spread among the clients and servers in the network

Front 2

Application
Logic

Back 2

(sometimes called business logic) Third function of application program can be simple or complex depending on application

Front 3

Client Server Architecture

Back 3

work is shared between the servers and clients
(dominate application software)

Front 4

Cluster

Back 4

a group of computers (often microcomputers) linked together so that they act as one computer

Front 5

Data Access Logic

Back 5

the second function of application program; the processing required to access data, which
often means database queries in SQL

Front 6

Data
Storage

Back 6

the first function of application program; most applications require data to be stored and retieved whether it is a small file such as a memo produced by a word
processor or a large database such as an organizations accounting records.

Front 7

Desktop
Videoconferencing

Back 7

with desktop videoconferencing, small cameras are installed on top of each users computer so that participants can hold
meetings from their offices

Front 8

Distributed Computing Model

Back 8

architecture that uses application systems written to use a Web browser as the client software, with Java Javascriptor AJAX downloaded as needed.

Front 9

Distribution
List

Back 9

a list of one or multiple email users

Front 10

Dumb
Terminal

Back 10

they do not participate in the processing of the data they display, have the bare minimum required to operate as input and output devices. Each keystroke is processed by the server.

Front 11

E-mail

Back 11

a networking application that allows users to send and receive mail electronically

Front 12

File Transfer Protocol (FTP)

Back 12

FTP enables users to send and receive files over the Internet. There are two types of FTP sites: closed and anonymous

Front 13

H.320

Back 13

is designed for room to room videoconferencing over high speed telephone lines

Front 14

H.323

Back 14

is a family of standards designed for desktop videoconferencing and just simple audio conferencing over the internet

Front 15

Host-based
Architecture

Back 15

the server (or host computer) performs virtually all of the work

Front 16

HTTP Request

Back 16

to get a page from a web server the web browser issues a special packet called an HTTP request

Front 17

HTTP Response

Back 17

once the server receives the HTTP request it processes it and send back

Front 18

Hypertext
Response

Back 18

will be the requested page or an error message

Front 19

Hypertext Markup Language (HTML)

Back 19

web text files or pages use a structural language called HTML to store their information. HTML
enables the author to define different types styles and sizes etc etc.

Front 20

Hypertext Transfer Protocol (HTTP)

Back 20

standard protocol for communication with a web browser and a Web server

Front 21

Instant Messaging (IM)

Back 21

exchange real time typed message or chat communication, works similarly to Web

Front 22

Internet

Back 22

the information superhighway. The network of
networks that spans the world

Front 23

Internet Mail
Access
Protocol (IMAP)

Back 23

an application-layer protocol standard that covers communication between an email client and an email server. The message is stored on server after read, most beneficial to users.

Front 24

Listserv

Back 24

a mailing list; One part, the processor, processes commands such as requests to subscribe, unsubscribe, or to provide more information about it. Second part is the mailer which receives messages and resends them to everyone

Front 25

Mail Transfer Agent

Back 25

with a two-tier client-server architecture, more commonly called
mail server software.

Front 26

Mail User
Agent

Back 26

with a a two-tier client-server architecture each client computer runs an application layer software called a mail user agent. More commonly called, a email client.

Front 27

Mainframe

Back 27

a very large general purpose computer that is capable of performing very many simultaneous functions, supporting very many simultaneous users, and storing huge amounts of data ($ millions)

Front 28

Microcomputer

Back 28

the type of computer you use. They are used as servers that can range from a small microcomputer, similiar to a desktop, to one costing
$20,000.

Front 29

Middleware

Back 29

software that sits between the application software on the client and the application software on the server

Front 30

MPEG-2

Back 30

designed for faster connections such as LAN or specially designed privately operated WAN. One of three standards within video transmission

Front 31

Multipurpose Internet Mail Extension (MIME)

Back 31

an application layer standard protocol that enables SMTP mail messages to transfer non text characters such as graphics and software. The sending email client translates the nontext
characters into something that resembles text using MIME codes and attaches it to the message. The receiving email client translates the MIME codes back into the original graphic or software file.

Front 32

Netscape

Back 32

in 1994, Marc Andreesen left NCSA to form Netscape. Forced NCSA to stop development of their Mosaic browser

Front 33

Network
Computer

Back 33

designed primarily to communicate using Internet-based standards (eg: HTTP, Java) but has no hard disk. It has only limited functionality.

Front 34

n-tier architecture

Back 34

uses more than three sets of computers

Front 35

Peer to Peer Architecture

Back 35

computers are both clients and servers and thus share the work

Front 36

Post Office Protocol (POP)

Back 36

one of two standards for communication between email client and mail server. Before a user can read a mail message the message must be copied
to the computers hard disk

Front 37

Presentation
Logic

Back 37

the fourth function of application program; presentation of information to the user and the acceptance of the users commans

Front 38

Protocol

Back 38

standard language among requests in web browsers.

Front 39

Request
Body

Back 39

contains information sent to the server, such as information that the user has typed into a form

Front 40

Request
Header

Back 40

contains a variety of optional information such as the Web
browser being used (Eg: Mozilla) and the date

Front 41

Request
Line

Back 41

starts with a command (eg: get) provides the Web page and end with the HTTP version number that the browser understands

Front 42

Response
Body

Back 42

web page itself

Front 43

Response
Header

Back 43

contains the HTTP a variety of optional information such as the Web server being used (Eg: Apache), the date, and the exact URL of the page in response

Front 44

Response
Status

Back 44

contains the HTTP version number the server used, a status code (Eg: 200 means "okay", 404 means "not found") and a reason phrase.

Front 45

Scalability

Back 45

refers to the ability to increase or decrease the capacity of the
computing infrastructure in response to changing capacity needs

Front 46

Server-Based
Architecture

Back 46

rely on mainframes; more expensive than client server architectures

Front 47

Simple Mail Transfer Protocol (SMTP)

Back 47

most commonly used email standard simply because it is the email standard used on the Internet. SMTP email is usually implemented as a
two-tier thick client-server application, but not always.

Front 48

SMTP
head

Back 48

lists source and destination email addresses as well as
the address itself, data, subject, and so on

Front 49

SMTP
body

Back 49

which is the word DATA followed by message itself

Front 50

Telnet

Back 50

enables users to log in to servers or other clients. Requires an application layer program on the client computer and an application layer program on the server or host computer.

Front 51

Terminal

Back 51

a device with a monitor and keyboard but no central processing unit (CPU)

Front 52

Thick
Client

Back 52

approach places all or almost all of the application logic on the client. AKA Fat client

Front 53

Thin
Client

Back 53

approach places little or no application logic on the client

Front 54

Three-tier
Architecture

Back 54

uses three sets of computers. The software on the client computer is responsbile for presentation logic, an application server is responsible for application logic, and a seperate database server is responsible for the data access logic and data storage.

Front 55

Transaction
Terminal

Back 55

designed to support specific business transactions such as the ATM used by banks or POS systems.

Front 56

Two-tier
Architecture

Back 56

uses only two sets of computers. The server is responsible for the data and the client, the application and presentation.

Front 57

Uniform Resource Locator (URL)

Back 57

specifies the Internet address of the Web server and the directory and name of the specified page wanted.

Front 58

Videoconferencing

Back 58

provides real time transmission of video and audio signals to enable people in two or
more locations to have a meeting

Front 59

Virtual
Server

Back 59

one computer (often a microcomputer) that acts as several servers. Using special software, several OS's are installed on same physical computer so that one physical computer appears as several different servers to the network

Front 60

World
Wide Web

Back 60

first conceived in 1989 by Sir Tim Berners-Lee at European Particle Physics Laboratory (CERN) in Geneva. Was first a database of information over this research.

Front 61

Web
Browser

Back 61

software package on application
layer. IE, Mozilla

Front 62

Web
Casting

Back 62

special type of one directional videoconferencing in which content is sent from the server to the user. At present, there are no standards for this technology

Front 63

Web
Server

Back 63

each server on the network that will act as a web server needs an application layer software packed called a web server. Microsoft and Apache