Operating systems Flashcards
Operating system (OS)
A piece of software that gives a computer instructions on how to work programs, and communicates with the hardware
User interface (UI)
The space where interactions between humans and machines occur
Graphical user interface (GUI)
A type of user interface that is comprised of icons, buttons, and menus that can be clicked to carry out tasks
Data compression
Lossy is when the quality of a file is reduced, and the original data is lost and cannot be regained. Happens with image files and audio files only. Often the lost quality and data is barely noticeable, and there is a large reduction in file size. Lossless allows the original data to be perfectly reconstructed from the compressed data, with no quality compromise, but often the reduction in file size is not so great
Defragmentation
When there is not enough space in the area closest to 1 on the drive, different segments of the file have to be spread across the drive and the drive is fragmented. Defragmentation involves collecting the different segments of the file and putting them into the same place on the drive
Buffer
Temporary storage that can be put into a computer where memory can be stored.
Interrupt
A signal that instructs the CPU to stop what it is doing and go to the task which is being prioritised
Encryption
Takes a message which can be read easily by a human and converts it into cipher text which cannot be read by a human easily. The cipher text must then be converted back to plaintext to be used and read easily
Backup
Creates a copy of it so if access to a device is lost then data can still be accessed from another device instead of being lost. Can be full (where everything is backed up in one go) or incremental (when data is backed up every certain time period)
Device driver
Device drivers are pieces of software that contain instructions on how to control a device/peripheral such as a mouse or a camera. Each connected device has its own driver.
