Unit 2 - Introduction to Mobile Apps & Pair Programming

Event Handler

A block of code that reacts to an event like a button click.

Horizontal Arrangement

A component used to display a group of components laid out from left to right.

byte

A group of eight binary digits or bits.

User Events

Actions by the user such as button clicks.

decimal number system

a base-10 system that we use every day, consisting of the symbols 0 through 9.

hexadecimal number system

a base-16 system, consisting of the 16 symbols 0 through 9 and A through F.

octal number system

a base-8 system, consisting of the symbols 0 through 7.

control structure

a block of programming statements that controls the flow or behavior of an algorithm.

NOT gate

a circuit with one input and one output defined such that its output is TRUE (or ON) when its input is FALSE (or OFF) and vice versa.

AND gate

a circuit with two inputs and one output defined such that its output is TRUE (or ON) only when both of its inputs are TRUE (or ON).

OR gate

a circuit with two inputs and one output defined such that its output is TRUE (or ON) when either or both of its inputs are TRUE (or ON).

flip flop

a digital circuit that has two states, ON or OFF, that can be used to store a 1 or a 0. It is the fundamental unit of computer memory.

abstraction

a general representation of something -- of some person or place or event or process. An abstraction extracts common features from specific examples in order to generalize concepts. Words, symbols, maps, and models are all examples of everyday abstractions.

network

a group of two or more computer systems linked together.

computer

a machine that processes information under the control of a program.

cyberspace

a metaphor for describing the non-physical terrain created by computer systems.

pseudocode

a notation for expressing algorithms, which is more precise that ordinary English but less formal than a programming language.

data center

a physical or virtual infrastructures used by enterprises to house computer, server and networking systems and components for the company's IT (information technology) needs.

algorithm

a precise sequence of instructions for processes that can be implemented by a programming language and executed by a computer.

browser

a program that displays web pages and is used to navigate the WWW.

machine language

a programming language that is directly readable by the computer's CPU.

high level language

a programming language that is human readable (App Inventor) and provides the programmer with easy to understand abstractions.

disk drive

a randomly addressable and rewritable storage device.

transistor

a semiconductor device used to amplify or switch electronic signals and electrical power. Transistors are the fundamental building blocks of electronic devices.

binary sequence

a sequence of 0s and 1s.

program

a sequence of instructions that controls the computer.

processor

a shorthand way of referring to a microprocessor or CPU.

bit

a single binary digit, either 0 or 1. It is the smallest unit of data in a computer.

social network

a social structure made of nodes that are generally individuals or organizations. A social network represents relationships and flows between people, groups, organizations, animals, computers, or other information/knowledge processing entities.

open standard

a standard (such as TCP, HTTP) that is not owned or controlled by a private entity. It stands in contrast to 'proprietary' materials', which are owned or controlled by a private entity. Open Standards fuel the growth of the Internet!

protocol

a system of rules that govern the behavior of some system.

data network

a telecommunications network which allows computers to exchange data.

flowchart

a visual (i.e. graphical) notation for expressing algorithms.

CPU

that part of the computer's hardware that carries out the instructions of a computer program.

data

the distinct information that is formatted in a special way. Exists in a variety of forms, like text on paper or bytes stored in electronic memory.

Internet

the global public network of independent and autonomous networks that are governed by the Internet Protocol Suite (TCP/IP

base

the number of distinct digits or symbols used to represent numbers in that system. Our decimal system is base-10 because it uses 10 digits, 0 through 9.

data abstraction

the practice of organizing and encapsulating certain data into a more general representation. An example would be storing the text 'hello' in a single variable rather than having numerous occurrences of 'hello' in a program.

Event-driven Programming

the program is activated by events such as button clicks.

Moore's Law

the projection that the number of transistors per square inch on integrated circuits will rougly double every year since the integrated circuit was invented.

HTTP

the protocol that controls the behavior of the WWW.

TCP/IP

the suite a protocols that determine the behavior of the Internet.

motherboard

houses the computer's main electronic components.

blacklist

In internet terminology, a blacklist is a generic term for a list of email addresses or IP addresses for organizations that known to be spammers.

UI Components

Parts of the user interface such as Buttons, Labels, etc.

If/Else

Selection or conditional algorithm that allows a program to choose between different actions.

User Interface

The part of computer application through which a user interacts with a program.

interpretation

The process of translating source code into machine language one instruction at a time and immediately executing instruction.

compilation

The process of translating the entire source code into a single binary file.

World Wide Web

an Internet application of interlinked web pages based on the HTTP protocol.

logic gate

an elementary building block of a digital circuit. Examples would be AND, OR, and NOT gates that perform basic digital operations.

overflow error

an error that occurs when the computer attempts to handle a number that is outside of the defined range of values can be represented

chip

an informal way of describing an integrated circuit (IC) consisting of millions of tiny circuits.

iteration

another term for 'repetition'

character

any symbol that requires one byte of storage.

variable

can be used to represent any number and is therefore more general and more abstract than a constant, such as the symbol 'X'.

general purpose computer

can run many different programs (e.g. a smartphone).

boolean

condition is a true/false condition. It is named after George Boole (1815-1864) an English mathematician.

software

consists of the programs that control the computer.

sequence

control structure is the application of each step of an algorithm in the order in which the statements are given.

repetition

control structure is the repetition of an algorithm for a specified number of times or until a true/false condition is met.

selection

control structure uses a true or false condition to determine which of two parts of an algorithm is used.

Output

data sent back from the program to the device and can be tactile, audible, visual, or text.

Input

data sent to a computer for processing by a program and can be tactile, audible, visual, or text

IETF

develops and oversees open standards such as HTTP (www) and SMTP (mail).

special purpose computer

has a fixed program (e.g. a simple calculator, a digital watch, a car's anti-lock braking system).

procedural abstraction

in computer science is the practice of organizing and encapsulating algorithms in named procedures that can then be invoked by name. An example would be the 'sqrt(x)', square root of x, which encapsulates the algorithm for calculating the square root of x.

Computing Innovation

includes a program as an integral part of its function. Can be physical, non-physical computing software, or non-physical computing concepts. For example, self-driving cars, picture editing software, e-commerce, a mobile app

hardware

includes its electronic and mechanical components that carries out the instructions of a computer program.

integrated circuit

informally, a chip, is an electronic circuit formed on a small piece of semiconducting material, that integrates billions of tiny transistors and logic gates.

Tim Berners-Lee

invented the World Wide Web (WWW).

whitelist

is a generic name for a list of email address or IP addresses that are considered to be spam free.

binary number system

number system in which all numbers are represented in terms of the 2 binary digits, 0 and 1.

intellectual property

refers to any property that is created using original thought. Traditional intellectual property include patents, copyrights, and trademarks.

IDE

software that provides comprehensive tools for programming such as UI design, code editing, and a way to interpret and run the program.

RAM

stores the computer's programs and data temporarily while power is on.

positional number system

such as our decimal system, the value of a digit in a number depends on its place. For example, in the decimal number 545, the leftmost '5' represents 500 because it occurs in the hundreds place, but the rightmost '5' represents 5 because it occurs in the ones place.

constant

such as the numeral '5', is an abstraction that represents a single thing, e.g., the value 5.