Understanding OS Fundamentals: Key Concepts of Operating Systems

Getting familiar with OS fundamentals is important to understand the workings of system programs and the interaction between various applications within the computer system. Operating systems manage hardware resources, and software applications and provide an interface and services for program execution. 

As the computer starts booting, the operating system comes into action and starts managing every application, even booting the computer to be ready for work. It is important to be well aware of the OS fundamentals if you are someone who uses computers frequently or works in a field related to computers. In this article, let us learn some of the most important os fundamentals and their importance. 

What is an Operating System?

Important Operating System Fundamentals 

1. Process Management 

• Process States: When a process makes the transition between different states during execution. Some of the important states of the process are new, ready, running, waiting, and terminated. 
• Process Control Block (PCB): A Process Control Block (PCB) consists of all important information of a process managed by the operating system. Some of the important components of PCB are Process ID, state, program counter (PC), CPU registers, memory management information, etc.
• Context Switching: Context switching is an important part of the operating system that saves the state of the current running process and loads the state of another process in the CPU.
• Inter Process Communication (IPC): IPC refers to a mechanism that allows processes to communicate and synchronize with each other in an active state. It is an important mechanism, especially for multi-process systems.

2. Memory Management

• • Paging: It is a memory management scheme that divides physical memory into fixed sized blocks also known as “frames” and logical memory into blocks of the same size known as “pages”. It is used to eliminate fragmentation and map logical to physical addresses in a computer.
  • Garbage Collection: Garbage collection is an automatic memory management process that reclaims unused memory allocated to objects no longer in use. It is available in Python and Java programming languages.
  • Segmentation: Segmentation is an important OS fundamental in memory management which divides memory into variable-sized segments based on the logical divisions of a program. It provides a logical view of memory and implements external fragmentation in the memory.
  • Virtual Memory: A technique that gives the illusion of a large main memory by using disk space to extend physical memory. It is used to implement paging and swapping. Execution of larger programs are completed in virtual memory.
  • Swapping: The process of temporarily moving a process or part of it from main memory to disk (and vice versa) to free memory. It is used to increase multitasking capability of a computer system.
  • Fragmentation: Fragmentation takes place when memory is used inefficiently, leading to gaps or unused memory space in memory allocation. There are two types of fragmentation i,e. Internal fragmentation and external fragmentation.
  • Cache Memory: A small and high-speed memory located close to the CPU that stores frequently accessed data for quick retrieval of processes.
  • Thrashing: Thrashing is a condition where excessive paging or swapping occurs which reduces the overall system performance. It might occur due to insufficient space in the main memory.

3. System Calls & Scheduling Algorithms 

• First Come First Serve (FCFS): The process that arrives first in the ready queue is executed first. It is a non-preemptive scheduling algorithm that suffers from the convoy effect in a short process. No context switching occurs in the FCFS algorithm.
• Shortest Job First (SJF): The process with the shortest estimated execution time is selected next for execution. It is a non-preemptive algorithm that consists of context switching and starvation of long processes.
• Shortest Remaining Time First (SRTF): The process with the shortest remaining execution time is executed next. It is a preemptive extended form of SJF. It also consists of starvation in long processes. 
• Round Robin Scheduling (RR): Round Robin Scheduling is one of the most popular scheduling algorithms which execute processes in a cyclic order with each process having a fixed time slice also known as quantum. It is a preemptive and effective scheduling algorithm.
• Priority Scheduling Algorithm: Processes in priority scheduling are scheduled based on priority, with higher-priority processes executed first. It can be preemptive or non-preemptive and consist of starvation in processes. 
• Longest Job First (LJF): Long Job First (LJF) executes the process with the longest execution time first. It is a non-preemptive algorithm.

4. Deadlock

5. Virtualization and Cloud Concepts In OS Fundamentals 

6. User Interfaces 

Relation Between DevOps And Operating System (OS)

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