1.5 Systems Software

Provides an interface between the user and the hardware.

• Application software • Utility programs • Memory management • File management • Device driver

The role of the OS to provide a platform for these to run. Eg. Word processors, spreadsheets, graphics programs.

• Allows for the transfer of data between memory. • The allocation of memory to applications. • Allows for multitasking as it lets more than one program be stored in memory at one time.

Allows users to: - Create, modify and delete files/folders. - Copy and duplicate files and folders. - Move files and folders. - Rename files and folders. - Sort items into different orders, according to name, file type, date created. - Search for particular files and folders - Restore deleted files. - Set access rights to files such as read only or edit.

Contains the instructions on how to control a peripheral device. E.g. printer

• Any device can be used with the OS, as long as there is a device driver for it. • Drivers can be updated, to give better performance.

• Allows individual users to be created and deleted • Different access levels to be given to different users • Keeps a log of files a user creates, accesses, edits and deletes.

To be able to run more than one program simultaneously.

• The OS can support multitasking. • The computer has enough memory to hold multiple programs in RAM at once.

Umbrella term for the way you interact with a computer as a human being.

• Graphical User Interface (GUI) • Command Line • Menu-driven • Natural language

• Windows, Icons, Menus, Pointers (WIMP) • Visual interface • Interactive, optimal for mouse and touch input. • Intuitive, easy for beginners • E.g. laptop

• Text based • Less resource heavy than GUI • More commands than GUI • Efficient • Typically for more advanced users • Useful for automating processes with scripts

• Successive menus presented to the user • Single options chosen at each stage • User limited to preset options • Often with buttons on a keypad • E.g. cashpoints, chip-and-pin devices

• Responds to questions in spoken language • Sometimes unreliable • Constantly improving • E.g. Hey Google, Siri, Alexa

Software used to maintain the computer system.

• Encryption software • Defragmentation software • Data compression software

An algorithm is used to scramble plain text into cipher text, which can only be made readable again by being decrypted with a key that only users have.

Takes fragmented files and rearranges them to collect files and free space together. This reduces movement of the read/write head across the surface of the disk, speeding up file access.

Reduces file size so that it takes up less space and is quicker to download. More files can be stored in memory.