software (4)

Created by

esther slade

Cards (20)

types of software 
application software
system software
application software 
allows the users to perform an activity such as creating a document, editing a photo or creating a web page
system software 
used to manage, maintain and run the computer itself including managing the hardware devices and the application software
system software divided into: 
operating system software
utility software
operating system (os) software 
manage the computers hardware and resources and manage and control application software
provide the user interface for the user to click icons or type commands, and allow application software to run
examples of os system 
microsoft windows
linux
iOS
unix
android
utility software 
used to perform maintenance and optimisation tasks
it is no essential
examples of utility software 
disk defragment
anti-virus
os interface might be: 
graphical user interface (gui) using windows, icons, meus and pointers
command line interface (cli) where commands are typed
dialogue based interface using voice commands
gesture based interface such as a touch interface or a virtual reality system
managing files 
the os is responsible for allocating space on secondary storage devices, and managing the creation and deletion of files
handling interrupts 
the os receives and processes requests from peripheral devices, known as interrupts. we will look at interrupts in more detail in another lesson
managing peripherals and drivers  
the os uses system software known as drivers to communicate with peripheral devices. each hardware devices such as a printer or a monitor will have its own driver software.
the os manages these and ensures they are correctly installed and up-to-date
providing a platform for running applications 
the os manages the programs that are running on the computer, allowing the user to start or stop programs and proving programs access to the resources they need (such as ram). the os also allows users to install, update and uninstall programs
managing memory 
the os controls the allocation of ram to indivitual programs, including dividing the allocation into pages. if the os allows multi-tasking, the os may need to use virtual memory to ensure programs have the required memory.
will involve swapping pages in and out of ram as necessary.
the os is also responsible for ensuring that one program cannot access the memory of another program, which would likely cause the computer to crash
managing multi-tasking 
operating systems can run multiple programs at once.
the os is responsible for switching between running tasks, allocating each of them some of the cpu's processing time.
the process of allocating processor time to tasks is known as scheduling.
operating systems can use different scheduling algorithms, including first come first served (fcfs), time slicing and shortest job first (sjf)
managing user accounts 
user accounts allow several people to have their own usernames and passwords to log on to a computer system. the os manages these accounts and ensures that one user cannot access files or resources that they do not have permission to access
providing system security 
the os provides general security for the computer. this includes ensuring users cannot access files or resources without the appropriate permission, and ensuring the computer is protected against unauthorised access over the internet, using suitable utility software as necessary (such as anti-virus programs)
the rom is the ideal location for the firmware because rom is non-volatile and it is not possible to change its contents. this software is known as firmware because it is software than it embedded in hardware.
as it helps the system boot and load the operating system, it is sometimes also called the bootloader
common names for firmware in pc's: 
BIOS - basic input output system
UEFI - unified extensible firmware interface
the firmware must be loaded before anything else
the operating system is then loaded by the firmware
any other software is then loaded by the operating system