Unit 2 - Introduction to Mobile Apps & Pair Programming (2019)

open standard

a standard (such as TCP, HTTP) that are not 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.

selection

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

CPU

CPU (Central Processing Unit) is that part of the computer's hardware that carries out the instructions of a computer program.

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.

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.

data network

a telecommunications network which allows computers to exchange data.

bit

short for binary digit, the smallest unit of information in a computer.

abstracting

the process of creating abstractions.

boolean

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

Event Handler

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

hardware

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

interpretation

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

compilation（编辑）

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

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.

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.

whitelist

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

blacklist

a generic term for a list of email addresses or IP addresses for organizations that known to be spammers.

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 than ordinary English but less formal than a programming language.

binary number system

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

algorithm（运算法则）

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.

flowchart

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

World Wide Web (WWW)

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.

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.

software

consists of the programs that control the computer.

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).

byte

8 bits

constant

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

User Events

Actions by the user such as button clicks.

WWW as a higher level of abstraction

Berners-Lee felt the WWW brought the Internet to a higher level of abstraction.

Event-driven Programming

In event-driven programming, the program is activated by events such as button clicks.

UI Components

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

abstraction layer

The Internet is organized into several abstraction layers that are controlled by various protocols. From the bottom up, we have the link layer (Ethernet protocol), the Internet layer (IP), transport layer (TCP), and application layer (HTTP)."

Internet

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

User Interface

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

motherboard

houses the computer's main electronic components.

RAM

implemented by one or more integrated circuits that comprise the computer's main memory where all data and programs are stored while the computer is on.

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).

general purpose computer

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

special purpose computer

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

data center

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

intellectual property

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

base

refers to 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.

IDE

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

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 one's place.

variable

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

sequence

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

Output

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

data

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

procedural abstraction

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.

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.

Moore's Law

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

HTTP

the protocol that controls the behavior of the WWW.

repetition

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

TCP/IP

the suite protocols that determine the behavior of the Internet.

octal number system

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