Includes operating system and utilities software. Tells computer hardware what to do and provides a user interface (OS). Maintains, optimises and cleans a computer (Utilities).
What is meant by an operating system?
A set of programs that controls how the user interacts with the hardware and software of a computer.
Name four commonly used operating systems
Windows, Mac OSX, Android, IOS
What is meant by a user interface?
Allows a user to interact with the computer.
What is meant by a Command Line Interface (CLI)?
The user has to type in specific commands to do things like moving and copying files.
What is meant by a Graphical User Interface (GUI)?
The user communicates with the operating system using windows, icons, menu and pointers (WIMP) e.g. Windows.
An example of a GUI
An example of a CLI
Operating systems have five functions - what are they?
Memory management/multitasking, providing a user interface, peripheral management and drivers, user management and file management.
Functions of an operating system: (Memory management)
The memory manager is in charge of the RAM. Programs often use RAM throughout their operation, some use more memory than others. The memory manager checks requests from programs for memory space are valid and then allocates memory space. It also de-allocates space.
Functions of an operating system: (Multitasking)
Windows, Linux, OSX and Android are multitasking operating systems. A multitasking operating system allows more than one program to run at the same time.
What is a peripheral?
Any input, output or storage device that connects to a motherboard. (keyboard, mouse, web cam, printer, hard disk drive)
Functions of an operating system: (Peripheral management)
Manages all of the computer input and output by managing requests from programs to use devices like printers, speakers, keyboards and hard disk drives. It communicates with devices through software called drivers.
What is meant by a device driver?
A driver is a piece of software designed to tell a peripheral what to do.
Functions of an operating system: (File management)
Controls files on system e.g. text, graphic files. Controls file permissions: to open a file, write to it and delete it. Helpful for security and to help organise files e.g. sorting. In windows file management is completed using windows explorer. (Right click the windows logo)
Functions of an operating system: (User management)
Computers often have several users. Operating systems allow for different accounts to be setup. The operating system can assign certain user access rights: - Read (view and open) but not change files or folders - Write: allows file/folder to be changed or deleted - Execute: gives user right to run an executable application.
Advantages of having different user accounts on computers
1. You can setup security for different users, particularly helpful with children. 2. Files can be made private from other users. 3. When browsing the internet, each user can have their own 'favourites' and bookmarks.
What is meant by utility systems software?
Software that is designed for security, maintenance, system optimisation and backup.
What is the purpose of anti-virus software (Utility systems software)?
For security - scans for and removes malicious files.
What is the purpose of encryption software (Utility systems software)?
For security - scramble data using a key to encrypt so it can't be understood. To decrypt a key is needed to put it into its original form.
What is the purpose of a firewall Utility systems software)?
For security - prevents unwanted access to or from a private network or the internet. Messages can be blocked based on criteria e.g. website addresses.
What is the purpose of spyware detectors (Utility systems software)?
For security - to block and remove programs designed to get your personal information.
What is the purpose of system clean-up tools (Utility systems software)?
For system optimisation - to search and remove files no longer needed.
What is the purpose of disk defragmentation (Utility systems software)?
For system optimisation - to rearrange parts of files on a hard drive that have become fragmented. This puts then back together for quicker access.
What is the purpose of file compression software (Utility systems software)?
For system optimisation - to make files smaller so they take up less space.
What is the purpose of backup programs (Utility systems software)?
For backing up - copying files to a second medium away from the originals for safe keeping.
What is a full backup?
All files are backed up - usually done on the first backup only.
What is an incremental backup?
New files or files that have changed since the last backup are backed up and kept with the original full backup
Why is compressing a file, so that it is smaller good?
1. Compressed files take less hard disk space. 2. Compressed files are quicker to attach to emails, upload and download.
What is meant by lossy compression?
Removes data to reduce the file size. When the file is uncompressed, only a part of the original information is still there (There will be some loss of quality). Examples: mp3 and jpeg.
What is meant by lossless compression?
As the file size is compressed, the quality remains the same - it does not get worse. Also, the file can be decompressed to its original quality. Examples: GIF and FLAC. File sizes are larger than lossy.
Why do we use a backup utility instead of copying and pasting files onto a memory stick?
Because it is automated, the users will not forget to backup to a designated drive. Automated backup saves the user time. Automatic backup means that it is less likely that files/folders will be missed.