System software (Chapter 5) Flashcards
What is the need for an operating system ?
- It provides a user interface
- It provides a platform for the software to run
- It hides the complexities of the hardware from the user
What are the key management tasks carried out by the operating system ?
- Memory management
- File management
- Security management
- Hardware management
- Process management
What is memory management ?
Memory management is a part of the operating system which controls the main memory
Memory management deals with the allocation of memory to processes in a computer.
It keeps track of all the allocated memory and all the free memory available in a system and determines when to allocate or deallocate memory and where to store the memory in a system. It also swaps data from the HDD to the SSD
It also decides how the memory will be stored and organizes it accordingly (paging/segmentation). It could be stored in one single place or contiguously as segments of fixed or variable lengths.
Furthermore, it also ensures that two processes aren’t occupying the same memory space at the same time as that would lead to data being lost or causing the computer to crash.
What is file management
File management is a part of the operating system that deals with the management of the files in a computer.
It divides the storage space into file allocation units and allocates space to particular files accordingly.
It maintains directory structures and specifies the logical method of file storage (like FAT or NTFS)
It provides the file naming conventions and controls and implements access rights
It also specifies the tasks that can be performed on a file (like open and close)
What is security management ?
Security management is a part of the operating system which ensures the integrity, confidentiality and the availability of data.
It achieves this by firstly helping to prevent illegal intrusion to the computer system by,
Carrying out OS system updates as and when they are available.
Ensuring that security software (like anti-virus software) are up to date and communicating with a firewall to check traffic.
It also ensures user authentication before they access any data by setting up user accounts with usernames and passwords and implementing access rights accordingly.
Finally, it provides automatic backup for data and allows the user to restore the system to its previous stable state by rolling back to it.
What is hardware management ?
Hardware management is a part of the operating system which controls all the input/output devices connecting to a computer.
It deals with the installation of appropriate driver software to allow communication between the device and the computer. It sends and receives data from the devices. It also handles the buffers to ensure smooth transfer of data between the devices. It also manages the interrupts from the devices by receiving them and managing them accordingly.
What is process management ?
Process management is a part of the operating system which manages the scheduling of processes.
It allows for multi-tasking and multi-processing, it ensures fair access and handles priorities.
It manages the resources the processes need and enables them to share information with one another. It also prevents interference between processes.
What is the purpose of utility software ?
- To help users maintain their computer
- For example, making memory allocation more efficient
- For example, checking the system for faults
What are the different utility softwares ?
- Disk formatter
- Disk repair software
- Defragmentation software
- Virus checker
- File compression
- Back-up software
What is a disk formatter ?
It is software which initializes and prepares a disk to store data on it, it does this by : -
Making any existing data inaccessible (by deleting it)
Partitioning the disk into logical drives
Sets up the file system
Checking for any errors on the disk
What is Disk repair software ?
It is software which checks for any errors or inconsistencies on a disk, resolves them.
It also retrieves data from a damaged disk and marks any bad sectors as unusable.
What is a virus checker ?
It is software which scans files stored on a computer system for malicious code,
It scans files when they enter the system and if they exhibit signs of a file with malicious software then they are isolated and deleted.
The program has to be regularly updated for new virus definitions and is constantly ran in the background or a schedule is set up for virus checking.
What is back-up software ?
It is software that makes a copy of data at regular intervals so that if it is lost/corrupted it can still be retrieved.
It can also store data on other external mediums like an external SSD or the cloud.
What is a program library ?
It is a set of pre-written and pre-tested subroutines which can be called in other programs by imported the library
What are the benefits of using a Dynamic Link Library ?
- The main memory requirements for the program is
reduced since the DLL is loaded only when required - The executable file size of the program using the DLL will
be smaller as the executable file does not contain all the
library routines - Maintenance is not needed to be done by the
programmer as the DLL is separate from the program - The main program doesn’t need to be recompiled when
changes are made to the DLL since they are
independent of each other - A single DLL file can be made available to several
programs which saves space in the memory
