Key Concepts in Computer Memory and Process Management

address binding

the process of mapping a program's symbolic addresses to physical addresses in memory

application software

programs designed to help users perform specific tasks, such as word processing, web browsing, or gaming

batch processing

a method of executing a series of jobs on a computer without manual intervention where tasks are processed in batches

base register

a register in the CPU that holds the starting address of the current memory segment; used in address translation

bounds register

a register that holds the ending address of a memory segment, ensuring that memory accesses stay within the allocated range

context switch

the process of storing and restoring the state of a CPU so multiple processes can share a single CPU

CPU scheduling

the method by which an operating system decides which processes should be executed by the CPU and in what order

demand paging

a memory management scheme where pages of data are brought into memory only when they are needed rather than in advance

dumb terminal

a simple display and input device with no processing power relying on a central computer for computing tasks

dynamic partition technique

a memory management method where memory is divided into variable-sized partitions based on the needs of processes

first-come, first-served (FCFS)

a CPU scheduling algorithm that processes requests in the order they arrive without priority

fixed partition technique

a memory management method where memory is divided into fixed-sized partitions, each holding one process

frame

a fixed-size block of physical memory used in paging systems to hold pages of virtual memory

logical address

an address generated by the CPU during a program's execution that is then translated to a physical address

mainframe

a large, powerful computer that can handle many simultaneous users and tasks, often used in enterprise environments

memory management

the process of controlling and coordinating computer memory, including the allocation and deallocation of memory spaces

multiprogramming

a method where multiple programs are loaded into memory and executed by the CPU concurrently to maximize resource use

non-preemptive scheduling

a CPU scheduling method where a running process is not interrupted and is allowed to finish before another process starts

operating system (OS)

the main software that manages computer hardware and software resources and provides services for computer programs

page

a fixed-size block of data in memory management representing a portion of a process's virtual address space

page map table (PMT)

a table used in virtual memory systems to track the mapping between virtual pages and physical frames

page swap

the process of moving pages between physical memory and disk storage to manage space in memory

paged memory technique

a memory management method that divides memory into fixed-size pages to minimize fragmentation and efficiently manage memory

partition memory management

a method of dividing memory into segments or partitions, each of which can hold a different process

physical address

the actual location in computer memory hardware where data is stored

preemptive scheduling

a CPU scheduling method where a running process can be interrupted and replaced by another process before it finishes

process

an instance of a running program, including its current state and memory information

process control block (PCB)

a data structure the operating system uses to store all information about a process

process management

managing the operating system's execution of processes, including their creation, scheduling, and termination

process states

the various stages a process goes through during its lifecycle, such as new, ready, running, waiting, and terminated

real-time system

a computing system that processes data and responds to inputs in a specific, often very short, time frame

response time

the time taken from the submission of a request to the start of the system's response

round-robin

a CPU scheduling algorithm where each process is assigned a fixed time slice in a rotating order

shortest job next (SJN)

a CPU scheduling algorithm that selects the process with the shortest expected execution time next

single contiguous memory management

a memory management method where all processes are loaded into a single contiguous block of memory

system software

software designed to provide a platform for other software, including operating systems and utility programs

thrashing

a condition where excessive paging operations occur leading to reduced system performance

time slice

a fixed amount of CPU time allocated to each process in a round-robin scheduling algorithm

timesharing

a method where multiple users can access a computer system concurrently by sharing time slices of the CPU

turnaround time

the total time taken from the submission of a process to its completion

virtual machine

software emulation of a physical computer, providing the same functionality as a physical machine

virtual memory

a memory management technique that creates an illusion of a large contiguous memory space by using disk storage to extend physical memory

absolute path

the complete and specific location of a file or directory in a file system, starting from the root directory

binary file

a file that contains data in a format that is not human readable; typically used to store executable programs or complex data structures

direct file access

the ability to retrieve or manipulate data from a file directly without sequentially accessing preceding data

directory

a container used to organize files into a hierarchical structure on a computer system

directory tree

a graphical representation or hierarchical structure of directories and subdirectories in a file system

disk scheduling

the method an operating system uses to efficiently schedule access to disk resources, aiming to reduce seek time and optimize performance

file

a named collection of data stored on a computer system, which can be text, an image, an executable, or any other type of information

file extension

a suffix attached to the end of a filename indicating the format or type of the file

file system

the method and data structure an operating system uses to organize and store files on storage devices such as hard drives

file type

the classification or category of a file based on its content and format that determines how it can be used or opened

path

a string of characters that specifies the location of a file or directory in a file system

relative path

a path that specifies the location of a file or directory relative to the current working directory

root directory

the top-level directory in a file system hierarchy, which contains all other directories and files

seek time

the time it takes for a hard drive's read/write head to move to the track where the data are stored

sequential file access

accessing data in a file by sequentially reading or writing from the beginning to the end

text file

a file that contains plain text characters, typically encoded in ASCII or Unicode, and is readable by text editors and word processors

working directory

the current directory in a file system from which a user or program is operating