Chapter 1
Computer systems
Computer system -Combination of all the components required to process and store data
using a computer
Hardware -Equipment associated with a computer
Software -Computer instructions that tells the hardware what to do
Programs-Instructions written by programmers
Programming-Writing software instructions
Application software -word processing, spreadsheets, payroll and inventory, games, app
System software- supports basic computer functions such as operating systems like
Windows, Android, Apple
Three major operations - Input – Processing – Output
Input – Data items (text, numbers etc.) placed in memory to be processed / hardware
devices
Processing – working with data (calculating, sorting…) done in Central Processing Unit
(CPU)
Output- information, data that’s been processed, sometimes stored on storage device (hard
drive, flash, cloud)
Programming language - Used to write computer instructions called program code (C#, C++,
Java) (source code)
Machine language- millions of on and off circuits (0/1), translated from program language
(object code)
Syntax -Rules governing word usage and punctuation
Syntax errors -Mistakes in a language’s usage
Computer memory -temporary, internal storage – random access memory (RAM)
Volatile memory – lost when the power is off
Non-volatile -permanent memory
Compiler/ interpreter -Translates source code into machine lang (binary lang) called object
code
Checks for syntax errors
Executes or runs -Input will be accepted, some processing will occur, and results will be
output
Programs with syntax errors cannot execute
Logical errors -Errors in program logic produce incorrect output
Logic of the computer program -Sequence of specific instructions in specific order
Variable -Named memory location whose value can vary
Computer systems
Computer system -Combination of all the components required to process and store data
using a computer
Hardware -Equipment associated with a computer
Software -Computer instructions that tells the hardware what to do
Programs-Instructions written by programmers
Programming-Writing software instructions
Application software -word processing, spreadsheets, payroll and inventory, games, app
System software- supports basic computer functions such as operating systems like
Windows, Android, Apple
Three major operations - Input – Processing – Output
Input – Data items (text, numbers etc.) placed in memory to be processed / hardware
devices
Processing – working with data (calculating, sorting…) done in Central Processing Unit
(CPU)
Output- information, data that’s been processed, sometimes stored on storage device (hard
drive, flash, cloud)
Programming language - Used to write computer instructions called program code (C#, C++,
Java) (source code)
Machine language- millions of on and off circuits (0/1), translated from program language
(object code)
Syntax -Rules governing word usage and punctuation
Syntax errors -Mistakes in a language’s usage
Computer memory -temporary, internal storage – random access memory (RAM)
Volatile memory – lost when the power is off
Non-volatile -permanent memory
Compiler/ interpreter -Translates source code into machine lang (binary lang) called object
code
Checks for syntax errors
Executes or runs -Input will be accepted, some processing will occur, and results will be
output
Programs with syntax errors cannot execute
Logical errors -Errors in program logic produce incorrect output
Logic of the computer program -Sequence of specific instructions in specific order
Variable -Named memory location whose value can vary
