Flashcards
ocr gcse computing - chapter 3
Flashcards do conjunto (72)
- 1What is software?Programs run on computers.
Stored as sets of instructions that that are given to the processor to carry out.
Also refers to the data that is used by the programs. - 2What is software like on a dedicated system? How is is stored/installed?Software is installed on a chip of some sort.
Specific to the job and is only changed when updated. - 3What is software like on a multi-purpose computer?Devices such as phones, laptops and tablets run different programs according to the wishes of the user.
- 4How is software stored/run on a multi-purpose computer?Stored on a secondary storage medium, such as a hard disk, memory stick or optical disk.
program is loaded onto RAM when required and the instructions are sent to the processor for decoding and execution. - 5What is system software?Software that controls the hardware
- 6What is application software?Handles real-world problems that the user wants to do, e.g. microsoft word, google chrome
- 7What is utility software?Used to maintain computer systems and has limited functionality.
- 8How is software produced?Produced using a programming language, or sometimes an automatic software generator.
- 9How is system software helpful to the computer?Stops application software don't have to take into account the precise movement of data between location.
With system software taking care of that, application programmers can concentrate of developing algorithms to solve real-world problems. - 10How does system software act as a link between the application and hardware?Hides the complexities of the hardware from the user and application programmer.
Allows the user to operate the computer without having to write programs. - 11What is an operating system?Main part of system software -
- 12what is the kernel?The heart of the operating system - part of the operating system that makes the hardware do things.
- 13What is the software stack?
- 14What is the user interface?The boundary between the human user and the machine.
It lets the user give commands, ask questions and displays a response.
Operating systems give new ways to do this, which are constantly being developed. - 15What is a command-line interface?A type of interface that requires the user to type commands.
The commands are translated by a command interpreter into signals that the computer will understand,
e.g. 'cal'=calender - 16How are commands used on the command line interface useful?You are able to completely control a computer with them.
Commands can also be grouped into shell scripts, to carry out maintenance jobs automatically. - 17What is a shell?Software that is needed to communicate with the kernel.
- 18What is a graphical user interface?An interface that uses images, known as icons to represent resources, files, programs and actions.
The user can click, touch or pinch these areas to make things happen.
The interface sits on top of the kernel and allows access to its features - 19Why are GUIs useful ways to interact with the computer?They are intuitive
No special training is required
Keyboard use is limited
No commands need to be learned - 20What kernel features does the GUI give the user access to?selecting software and files
sending messges
controlling volume
connecting to wifi
deleting/moving files
updating/installing software - 21What is touch screen interface?Designed for phones/tablets/latops etc
Not designed for mouse or hardware keyboard input, but respond to various actions of the fingers. - 22What are natural language and speech interfaces?Interfaces that accept normal speech input.
These can be difficult to get right as speech varies on accent, talking speed, dialect, clarity of diction - 23Speech input is useful for:Selecting options on telephone menus
Giving commands to a computer
dictating texts
e.g. it is used to recognise subtitles on tv programs - 24What do operating systems have to do to memory?Decide what goes where in the memory,
make sure that memory is used efficiently and important data is not overwritten during the running of the program. - 25What are pages?Blocks of memory/virtual memory that memory is devided into in order to be organised, used efficiently and not overwritten, created by the operating system.
- 26What is a process?A program that is being executed.
The process is loaded onto a vacant page when the job needs to be done.
The OS protects it so it is not overwritten whilst being used. - 27What is virtual memory?'Not real' memory that uses secondary storage (the disk) to hold parts of a program that are not currently being used, to save space in the main memory.
It is also slower to access the main memory. - 28What are modules?What a large program that is not in use s split into if it uses to much memory.
Stored separately on secondary storage
When a module is needed, it is loaded into memory and run as a process.
When a different module is needed, it can overwrite an unused module. - 29What is a file?A named store of data on a secondary storage medium.
- 30What are data files?File storing things such as a word processed document or database.
- 31What are program files?Holds things such as operating system components and applications.
- 32What is configuration data?Files that holds things such as parts of the windows registry.
- 33How do OS's control files?Keeps track of all files in the system.
Files are stored on secondary storage.
Copied into main memory when needed.
When a file is saved, the OS looks up where there is free space, writes the data to the medium and makes a record of where it is located.
Next time the file is needed, the OS looks up its location, and retrieves it. - 34How and why are files segmented.Like main memory, secondary memory is split into segments, and files are often larger than these segments, so have ti be split into blocks across many segments, which could be anywhere in the storage medium.
If a file is split into many locations, it could take longer to write to and retrieve.
Each block contains info on the next block, making it easier to retrieve the file. - 35What is defragmentation?A process used to tidy up the storage medium so that parts of a file are moved to be stored next to each other, as access to file slows down.
- 36What are device drivers?Software that creates an interface so that programmers do not need to be concerned about the peculiarities of inputs and output devices that are connected to computers.
Allows the OS to communicate with the device, and allows devices to operate independently of each other.
Device drivers are developed by manufacturers so input and output devices could be accomodated. - 37What is multiprogramming?When an all-purpose computer has several programs loaded into memory at the same time.
- 38What is multitasking?When it is seemed to the user that multiple processes are being carried out at the same time, when really, the OS is switching between the processes, often so fast that the user doesn't notiice.
- 39A multiprogramming operating system must?Make sure the CPU is in use as much time as possible.
Try to speed up the operation of all tasks.
Shares resources fairly between tasks. - 40What is a scheduler?A system used by an OS used to allocate time when there are several processes sharing a single processor.
The allocation is made according to a policy, e.g. carrying out the shortest job first, all jobs get equal time, first come first served, or allocating priorities. - 41What are file systems?Ways in which OSs organise files on secondary storage - most using hierarchical systems.
Files are stored in directories, and the directories can include subdirectories. - 42What is a directory?a logical grouping of files. In windows systems, they are called folders.
- 43Why are directories useful?Make it easier for a human user to locate related files.
Allow the repeated use of the same file name for different locations. - 44What are file extensions?Parts of the file name that indicate what type of file it is.
- 45what does 'doc' stand for?word document
- 46What does 'PDF' stand for?Portable document format - used to store documents in a defined format
- 47What does HTML stand for?HyperText Markup Language - created web pages
- 48what does 'jpg' stand for?Joing Photographic Experts Group - compressed image file format
- 49What does 'mp3' stand for?Moving pictures expert group audio layer 3 - common music file format using lossy compression
- 50What are attributes?Data about a file that provides extra data about it, e.g. creator, who can view/edit it, whether it is read-only, size, archived etc
- 51What are viruses?Programs that replicate and attach themselves to legitimate programs - often have a payload designed to damage files, control the computer, retrieve confidential data.
Some viruses have no payload but still cause damage. - 52What is authentication?The set up of the OS
- 53What are privileges?RIghtas assigned to user and groups. Include features such as whether for a particular file a user can read, write, or execute it.
- 54What is encryption?When a file is transformed so an unauthorized person cannot understand them.
User passwords can sometimes be found in an encryption of a file. - 55What are text editors?cut -down word processors that allow text to be created, saved, read and changed. They do not save extra data characters, such as formatting information.
Useful for writing the source code of programs and editing configuration files.
All OS's come with editors as standard. - 56What are linkers?Combine modules of object code (complied program code) into a single executable program.
- 57What are interpreters?Convert types commands into machine instructions that the processor understands to be executed.
- 58What are applications?Programs that people use to do real-world jobs. e.g. word processors, autopilot, traffic light controls, games, mp3 players etc
- 59What are utilities?Software tools that help make maintaining the system easier.
Most OS's come with bundles of utilities. - 60What common utilities are there?Antivirus - detect and remove virsuses.
Spyware protection - checks for and removes programs recording internet history.
Firewalls - monitor traffic flowing through system
desk organisation
System cleanup tools - 61What is customer written software?Software specially commissioned for a particular customer
- 62Advantages of customer written software?Has the exact features required
Should not require special adaptions
Maintenance contract can be agreed with developer.
developer can be contacted to solve issues/provide training - 63Disadvantages of customer written software?May not be extensively tested.
Expensive - developer makes profit from just one customer
may take a long time to develop. - 64What is off the shelf software?Software sold to many that is already packaged and ready to install.
- 65advantages of off the shelf software?ready immediately
Extensively tested
forums online to give advise on system problems
low cost - 66disadvantages of off the shelf software?wont be exactly what the customer needs
may need extensive customization
customer may need to find training providers - 67What is open source software?Software placed in public domain by developers - often produce software to improve skills or for public's benefit.
- 68Advantages of open source software?may be free
can be altered with easy access source code
many work to improve it - highly efficient and reliable. - 69Disadvantages of open source software?no maintenance contracts
no one to contact in case of problems
updates come at irregular intervals or not at all
Software works on different platforms that company owns - 70What is proprietary software?Software developed by a company for profit.
Source code detained as valuable trade secret. - only compiled code is released - user buy license to use it. - 71Advantages of proprietary software?Help when there is a problem
extensively tested
updates come regularly - 72disadvantages of proprietary software?Expensive
Deliberate incompatabilities may be introduced so user get locked in
inflexible to users needs.
Informações
- Descrição
- GCSE Computer Science FlashCards sobre ocr gcse computing - chapter 3, criado por Alice Lang em 06-03-2017.
- Criado por
- Alice Lang · mar 2017
- Atualizado
- 6 mar 2017
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