What is software, and the two kinds of it?
Software is the programs running on a computer system, the two kinds are:
- Application Softwares
- For User Benefits
- System Softwares
- For Hardware and other software to operate.
- Game Engines; Utility Programs
What is the Operating System?
It is the essential software that links hardware and other software together and manages the computer system.
- Manages Hardware
- Manages Applications
- Creates a user Interface
- Provides a layer of security
What does the OS do?
- User Management
- Peripheral Management
- File Management
- Memory Management
- Process Management
What is the User Interface, and the two kinds?
- Command-Line Interface
- A shell responding to successive text commands
- More direct and compact
- Graphical User Interface
- uses Icons and other Visual Indicators
What is Process Management?
A single-tasking Operating System can only execute 1 process at a time, which means it needs to know when it must switch. Process Management includes interrupts.
A multi-tasking OS still executes only 1 process but allows multiple apps to run by rapidly switching. An OS uses CPU time for the processes, and prioritizes them.
What is Memory Management?
When a program is opened, it needs to be copied into the RAM. The OS oversees the allocation and management of RAM space, and decides when virtual memory is needed.
What is Peripheral Management?
Peripheral Devices are supplementary hardware, like keyboards, printers and cameras. The OS uses device drivers, which convert the signals from the peripheral signals into a signal the OS can understand. A driver is an interface, which hides the complexities of the hardware.
What is User Management?
It is the management of usernames; passwords, and account creation. In multi-user OSs, there are user account controls.
What is File Management?
The OS manages records of all files and their location, and allows what each user can access.
What is Utility Software?
Utility Software analyses, configures, optimises or maintains a system.
What are the kinds of Utility Software?
- Encryption Software
- Encrypts and Decrypts Files
- Data Compression Software
- Reduces File Sizes
- Backup Software
- Defragmentation Software
- File Converters
- Repairing Files
- Anti-Viruses
- Anti-Spyware
What is Backup Software?
Full-Backup:
- Creates copies of all files
- slower to backup, faster to restore
Incremental Backup:
- Data created after previous backup is copied
What is Defragmentation?
Data is stored in hard disks wherever there is space, this can scatter the data. Defragging reorganizes related data, so they can be accessed faster - it makes the data continuous again.
What is Defragmentation Software?
Data in hard disks are written in whichever part is empty, this causes the data to be fragmented. Defragmentation rearranges the data so it becomes continuous again.
What are File Converters?
They change data from one format to another.
What are repairing files?
A file can get corrupted if data is missing or not organized properly. By viruses, crashes or bugs.
What is an Anti-Virus?
Anti-Virses detect and remove malware and prevent them from being installed as well as giving real-time protection. It doesn’t only protect from viruses.
What is Anti-Spyware?
Anti-Spyware may contain databases of known spywares.
What is a software model?
Software models are used to simulate aspects of the real world. It can be like weather forecasting, nuclear physics, economical forecasts.
How do you build a software model?
- Work out what connects aspects of the real problem
- Make assumptions and simplify the problem
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1.1 Algorithms9
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1.2 Decomposition and Abstraction3
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3.1 Binary (incomplete)6
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3.2 Data Representation23
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4.1 Machines and Computational Teaching2
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4.2 Hardware37
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4.3 Logic6
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4.4 Software20
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4.5 Programming Languages9
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5.1 Networks37
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5.2 Network Security21
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5.3 The Internet and The World Wide Web10
