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neurologyYou need to know

• An operating system is system software that manages computer hardware, provides a platform for applications and allows users to interact with a computer.
• A user interface allows a user to communicate with a computer by entering commands or selecting options and receiving output.
• A graphical user interface uses features such as windows, icons, menus and a pointer, while a command-line interface requires users to type commands.
• Memory management controls the transfer of data and instructions between secondary storage, main memory and the processor.
• The operating system allocates areas of main memory to applications and prevents them from interfering with memory used by other processes.
• Multitasking allows several applications to appear to run at the same time by managing their use of memory and processor time.
• Peripheral management controls communication between the processor and devices such as keyboards, printers and storage drives.
• A device driver is software that translates operating-system instructions into commands that a particular peripheral can understand.
• User management creates and maintains user accounts, including usernames, passwords, access rights and security settings.
• Access rights determine which files, folders, applications and system settings each user is permitted to access or change.
• File management allows users to name, save, copy, move, rename, organise into folders and delete files.
• The operating system records file locations and provides a hierarchical folder structure so that stored data can be organised and retrieved.
• Utility software performs maintenance, security and housekeeping tasks that may not be provided fully by the operating system.
• Encryption software converts plaintext into ciphertext using an encryption key, preventing unauthorised users from reading the data.
• Encrypted data must be decrypted with the correct key before it can be read in its original form.
• Defragmentation reorganises fragmented parts of files on a magnetic hard disk so that each file is stored in contiguous blocks, which can improve access speed.
• Data compression reduces a file's size so that it uses less storage space and can be transferred more quickly.
• Lossless compression allows the original data to be reconstructed exactly, whereas lossy compression permanently removes some data to achieve a greater reduction in file size.

• Identify operating-system functions from descriptions of user interface, memory, peripheral, user and file-management tasks.
• Explain how an operating system allocates memory and processor time to enable multitasking.
• Trace how an operating system manages the transfer of data between a peripheral, main memory and the processor.
• Explain how a device driver enables the operating system to communicate with a specific peripheral.
• Configure appropriate user accounts and access rights for a given scenario, restricting files and settings to authorised users.
• Organise files using meaningful names and a logical hierarchy of folders, then save, copy, move, rename and delete them correctly.
• Select and justify encryption, defragmentation or data compression for a given problem by linking the utility's function to the user's need.
• Compare lossless and lossy compression and choose an appropriate method based on required file size and data quality.