MANISYSPrefinals

E-Commerce

- commercial transactions conducted electronically on the Internet.

-  is trading in products or services using computer networks, such as the Internet. 

6 Elements in practicing

Ecommerce

Ecommerce

displaying product information/pictures clearly

offering multiple payment options providing telephone support including  postage & GST in purchase

price giving a money back guarantee working on a secure platform.

Ecommerce Categories Business - to - Business (B2B) Business - to - Consumer (B2C) Consumer - to - Consumer (C2C) Consumer - to - Business (C2B) Business - to - Government (B2G) Government - to - Business (G2B) Government - to - Citizen (G2C)

MANAGING DIGITAL DATA

Managing Digital Data

ANALOG

Waves that illustrate the loudness of a sound or the brightness of the colors in an image at a given moment in time.

Analog-to-Digital Converter Chip

Converts analog signals into digital signals.

Base Transceiver Station

A large communications tower with antennas, amplifiers, and receivers/transmitters.

BLUETOOTH

A type of wireless technology that uses radio waves to transmit data over short distances (approximately 30 feet for Bluetooth 1 and 60 feet for Bluetooth 2). Often used to connect peripherals such as printers and keyboards to computers or headsets to cell phones.

CELLPHONE (Cellular Phone)

A telephone that operates over a wireless network. Cell phones can also offer Internet access, text messaging, personal information management (PIM) features, and more.

CODEC

A rule, implemented in either software or hardware, which squeezes a given amount of audio and video information into less space.

DATA PLAN

A connectivity plan or text messaging plan in which data charges are separate from cell phone calling charges and are provided at rates different from those for voice calls.

DERIVATIVE WORK

Intellectual property that is based on an original work but is modified in some way.

DIGITAL SIGNAL PROCESSOR

A specialized chip that processes digital information and transmits signals very quickly.

ELECTRONIC TEXT (ETEXT)

Textual information stored as digital information so it can be stored, manipulated, and transmitted by electronic devices.

Ereader

A device that can display etext and has supporting tools, like note taking, bookmarks, and integrated dictionaries.

FLASH MEMORY

Portable, nonvolatile memory.

GLOBAL POSITIONING SYSTEM (GPS)

A system of 21 satellites (plus 3 working spares), built and operated by the U.S. military, that constantly orbit the earth. They provide information to GPS-capable devices to pinpoint locations on the earth.

HIGH DEFINITION (HD)

A standard of digital television signal that guarantees a specific level of resolution and a specific aspect ratio, which is the rectangular shape of the image.

INTERNET TABLET

A very light, portable computing device without a keyboard.

MICRO BROWSER

Software that makes it possible to access the Internet from a smartphone.

MULTIMEDIA MESSAGE SERVICES (MMS)

An extension of short message service (SMS) that enables messages that include text, sound, images, and video clips to be sent from a cell phone to other phones or e-mail addresses.

NETBOOK

A computing device that runs a full-featured operating system but weighs two pounds or less.

PEER-TO-PEER SHARING

The process of users transferring files between computers.

PORTABLE MEDIA PLAYER (PMP) A small portable device (such as an iPod) that enables you to carry your MP3s or other media files around with you.

RESOLUTION

The clearness or sharpness of an image, which is controlled by the number of pixels displayed on the screen.

SHORT MESSAGE SERVICE (SMS)

Technology that enables short text messages (up to 160 characters) to be sent over mobile networks.

SMARTPHONE

A device that combines the functionality of a cell phone, a PMP, and a PDA into one unit. Smartphones have sophisticated operating systems, Web browsers, and the capability to run software applications.

TETHERING

Approach which makes sure that as long as you have a 3G signal, your computer can access the Internet even when it tells you there are no available wireless networks. Several smartphones offer this capability.

VOICE OVER INTERNET PROTOCOL (VoIP)

A technology that facilitates making telephone calls across the Internet instead of using conventional telephone lines.

WIRELESS INTERNET SERVICE PROVIDER

An ISP that provides service to wireless devices such as PDA/smartphones.

WIRELESS MARK-UP LANGUAGE (WML)

A format for writing content viewed on a cellular phone or personal digital assistant (PDA) that is text-based and contains no graphics.

DATABASE MODELS

Database Model

Define the logical designs of a data. The models describes the relationships between different parts of data.

Examples of Database Models

Hierarchical model Network model Relational model

Hierarchical model

In this model, each entity has only one parent but can have several children. At the top of hierarchy there is only one entity which is called root.

Example of hierarchical model

Network Model

In this model, entities are organized in a graph, in which some entities can be accessed through several path.

Example of network model

Relational Model

In this model, data is organized in two-dimensional tables called relations. The tables or relations are related to eahc other.

Example of relational model

Components of DBMS

HardwareThe physical computer system that

allows physical access to data Software

The actual program that allows users to access, maintain, and update physical data

Data: stored physically on the storage devices

User: include end users and application programs

ProcedureA set of procedures (rules) that should be clearly defined and followed by the users of the database

Relational Operations

Select (originally called restrict) Project Union Intersect Difference Divide

Database Architecture Internal level

The internal level determines where data are actually stored on the storage device

Conceptual levelThe conceptual level defines the logical view of the data

External levelThe external level interacts directly with the user