Chapter 1 Key Terms CMSC 140

Program

Set of instructions that a computer follows to perform a task

Software

Program is often referred to as, without software computer can’t do anything

Hardware

Physical components of a computer, CPU, main memory, secondary storage, input and output devices

Central Processing Unit

Part of computer that runs the programs, most important component of a computer, without it no software can run

ENIAC

First programmable computer, used by US Army for ballistic calculations

CPU Job

Fetch instructions, follow instructions, produce a result

CPUs 2 parts

Control Unit & Arithmetic Logic Unit

CPU Control Unit

Coordinate’s all of CPU’s operations

CPU Arithmetic Logic Unit

Designed for mathematical operations

Fetch/Decode/Execute Cycle

When a computer runs a program this engages

Fetch

Control Unit fetches next instruction from main memory

Decode

Instruction is encoded in number format, control unit decodes the instruction & generates an electronic signal

Execute

Electronic signal is routed to the appropriate component, and that component performs the operation

Main Memory

Where a computer stores a program while it’s running

Random-access-memory (RAM)

What main memory is known as, it’s called this because the CPU is able to quickly access data stored at any random location in random-access-memory

When computer is turned off

RAM is erased

What is computer memory divided into?

Bytes

Bytes

Have enough memory to store a letter of the alphabet

Bit

Stands for binary digit, each one has a unique number assigned to it, known as an address

Secondary storage

Can hold data for long periods of time, even when computer is off

Most common type of secondary storage

Disk drive, which stores data by magnetically encoding it onto a circular disk

SSD

Solid state drive, which has no moving parts and operates faster than a traditional disk drive

Input Device

Device that collects data from outside world and sends it to the computer

Output Device

Anything the computer sends to the outside world

System Software

Programs that control and manage the basic operations of a computer

Operating System

Type of system software, controls internal operations of the computer’s hardware, manages devices connected to the computer, most fundamental program on a computer

Utility Programs

Type of system software, performs specialized task that enhances computer’s operation or safeguard data.

Application software

Programs that make a computer useful for everyday tasks, apps

Algorithm

Set of well-defined steps for performing a task or solving a problem

Machine language

Uses binary numbers (0,1)

Low-level programming languages

Close to level of CPu, uses more numeric machine language than words

High-level programming languages

Closer to human readability, easiest languages to learn

Program Portability

Ability to write a program on one computer and run it on other systems

Source code

Statements written by programmer, saved in a source file

First step in translating source code to machine language

Preprocessor reading source code

2nd step in translating source to machine language

Compiler steps through preprocessed source code, translating each source code instruction into the appropriate machine language instruction.

What uncovers syntax errors?

The compiler

What are translated machine language instructions called?

Object code

What does the linker do?

Combines object file with the library routines, and afterwards an executable file is created

Describe an IDE

A suite that has a text editor, compiler, debugger, and more all incorporated into one

Common elements of programming languages

Key words, programmer-defined identifiers, operators, punctiation, syntax

What is a statement?

Complete instruction that causes the computer to perform an action

Variable

Named storage location in the computer’s memory for holding a piece of info. stored in RAM

What are the two types of data in programming?

Numbers & characters

What’s a variable definition?

Name given to a variable

What is the 3-step primary activity of a program?

Input, processing, output

What does the programming process consists of?

Design, creation, testing and debugging activities.

What is software engineering?

The entire process of crafting computer software

What is procedural programming?

Programmer creates procedures (functions), the procedures are statements that perform a specific task

What is object-oriented programming?

Programming that’s focus on the object

What are Objects?

Elements that have info and the ability to manipulate the info, operations are carried out on the object by sending a message