1. Operating System (OS) Definition
An operating system is software that acts as an intermediary between computer hardware and
users. It manages hardware resources and provides services for computer programs.
2. Functions of an Operating System
Process Management: Handles the creation, scheduling, and termination of
processes. The OS ensures that each process gets enough CPU time and manages
process synchronization and inter-process communication.
Memory Management: Manages the computer's memory, including RAM and cache.
It tracks memory allocation, deallocation, and addresses memory protection.
File System Management: Manages files on the disk. This includes creating, reading,
writing, and deleting files, as well as organizing them into directories.
Device Management: Controls hardware devices through drivers, allowing the OS to
communicate with peripherals like printers, disks, and network interfaces.
User Interface: Provides a user interface (UI), which can be command-line based or
graphical (GUI), allowing users to interact with the computer.
3. Types of Operating Systems
Batch Operating Systems: Processes jobs in batches without user interaction.
Common in early computing.
Time-Sharing Operating Systems: Allow multiple users to share system resources
simultaneously, providing the illusion of dedicated access.
Distributed Operating Systems: Manage a group of distinct computers and make
them appear as a single coherent system to users.
Real-Time Operating Systems: Provide immediate processing and response for
critical applications, often found in embedded systems.
4. Process and Thread Management
Process: A program in execution, which includes the program code, current activity,
and its resources.
Thread: A lightweight process that can run concurrently with other threads within the
same process, sharing the same resources.
5. Concurrency and Synchronization
Concurrency refers to the execution of multiple processes or threads at the same time.
Synchronization is necessary to avoid conflicts when processes or threads access shared
resources.
6. Deadlocks
A situation where two or more processes are unable to proceed because each is waiting for
the other to release a resource. Operating systems use various strategies to prevent or resolve
deadlocks.
An operating system is software that acts as an intermediary between computer hardware and
users. It manages hardware resources and provides services for computer programs.
2. Functions of an Operating System
Process Management: Handles the creation, scheduling, and termination of
processes. The OS ensures that each process gets enough CPU time and manages
process synchronization and inter-process communication.
Memory Management: Manages the computer's memory, including RAM and cache.
It tracks memory allocation, deallocation, and addresses memory protection.
File System Management: Manages files on the disk. This includes creating, reading,
writing, and deleting files, as well as organizing them into directories.
Device Management: Controls hardware devices through drivers, allowing the OS to
communicate with peripherals like printers, disks, and network interfaces.
User Interface: Provides a user interface (UI), which can be command-line based or
graphical (GUI), allowing users to interact with the computer.
3. Types of Operating Systems
Batch Operating Systems: Processes jobs in batches without user interaction.
Common in early computing.
Time-Sharing Operating Systems: Allow multiple users to share system resources
simultaneously, providing the illusion of dedicated access.
Distributed Operating Systems: Manage a group of distinct computers and make
them appear as a single coherent system to users.
Real-Time Operating Systems: Provide immediate processing and response for
critical applications, often found in embedded systems.
4. Process and Thread Management
Process: A program in execution, which includes the program code, current activity,
and its resources.
Thread: A lightweight process that can run concurrently with other threads within the
same process, sharing the same resources.
5. Concurrency and Synchronization
Concurrency refers to the execution of multiple processes or threads at the same time.
Synchronization is necessary to avoid conflicts when processes or threads access shared
resources.
6. Deadlocks
A situation where two or more processes are unable to proceed because each is waiting for
the other to release a resource. Operating systems use various strategies to prevent or resolve
deadlocks.
