Operating Systems

• When allocated memory is larger than what is actually needed:

  Internal Fragmentation
• When there is enough space to run a process but the available memory is divided into small non-contiguous blocks:

  External Fragmentation
• The main software that manages all the software and hardware in a computer:

  Operating System
• Where information about a process is stored:

  Process Control Block (PCB)
• The excessive swapping of data between physical memory(Ram) and virtual memory(disk storage):

  Thrashing
• The rearranging of memory blocks to minimize fragmentation and optimize memory usage:

  Compaction
• A signal sent to the processor about a process that requires immediate attention:

  Interupt
• Allow the computer to temporarily increase the capacity of main memory by using secondary memory:

  Virtual Memory
• An error that occurs when a process requests a page that is not currently in physical memory:

  Page Fault
• Method of moving pages between physical memory and disk storage to manage memory resources:

  Page Swapping
• The smallest unit of data storage on a disk:

  Sector
• High-speed memory storage used to temporarily store frequently accessed data or instructions for faster retrieval by the processor:

  Cache
• A technique of gradually increasing the priority of processes that wait in the system for a long time:

  Aging
• Component of the operating system responsible for selecting processes from the job queue and allocating resources for execution:

  Job Scheduler
• State or condition of a job in the system, indicating whether it is waiting, running, or completed.

  Job Status
• A technique that allows multiple processes to be executed simultaneously by the processor:

  Multiprogramming
•  A scheduling policy where the operating system can interrupt and switch tasks at any time:

  Preemptive
• A scheduling policy where a task must voluntarily relinquish control before another task can start.

  Non-Preemptive
• The component responsible for selecting processes from the ready queue for execution based on scheduling policies and priority.

  Process Scheduler
• Rules or algorithms are used by the process scheduler to determine the order in which processes are selected for execution:

  Process Scheduler
• Hardware component responsible for executing instructions and processing data in a computer system.

  Processor
• Set of instructions or code that performs a specific task when executed by the processor:

  Program
• An instance of a program in execution, including code, data, and variables, with its own memory space and execution context.

  Process
• Data structure used to organize and manage processes or tasks based on specific criteria like priority or arrival time.

  Queue
• Process Control Block

  Information about a process stored by the operating system.