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Spooling:- Spooling is the process of a sending data to a spool, or temporary storage area in the computer’s memory. This data may contain files or processes. Like a spool of thread, the data can build up within the spool as multiple files or jobs are sent to it. However, unlike a spool of thread, the first jobs sent to the spool are the first ones to be processed (FIFO, not LIFO).

The most common type of spooling is print spooling, where print jobs are sent to a print spool before being transmitted to the printer. For example, when you print a document from within an application, the document data is spooled to a temporary storage area while the printer warms up. As soon as the printer is ready to print the document, the data is sent from the spool to the printer and the document is printed.
Semaphore:-

Semaphores:- These  are commonly use for two purposes: to share a common memory space and to share access to files. Semaphores are one of the techniques for interprocess communication (IPC). The C programming language provides a set of interfaces or “functions” for managing semaphores.

In programming, especially in Unix systems, semaphores are a technique for coordinating or synchronizing activities in which multiple processes compete for the same operating system resources. A semaphore is a value in a designated place in operating system (or kernel) storage that each process can check and then change. Depending on the value that is found, the process can use the resource or will find that it is already in use and must wait for some period before trying again. Semaphores can be binary (0 or 1) or can have additional values. Typically, a process using semaphores checks the value and then, if it using the resource, changes the value to reflect this so that subsequent semaphore users will know to wait.
Swapping:- Swapping concept comes in terms of process scheduling. Swapping is basically implemented by Medium term scheduler.Medium term scheduler removes process from CPU for duration and reduce the degree of multiprogramming. And after some time these process can again be reintroduced into main memory. Process execution will again be resumed from the point it left CPU. This scheme is called swapping. More generally we can say swapping is removing of process from memory to secondary memory and again back to main memory.

Spooling:-

Spooling is the process of a sending data to a spool, or temporary storage area in the computer’s memory. This data may contain files or processes. Like a spool of thread, the data can build up within the spool as multiple files or jobs are sent to it. However, unlike a spool of thread, the first jobs sent to the spool are the first ones to be processed (FIFO, not LIFO).
The most common type of spooling is print spooling, where print jobs are sent to a print spool before being transmitted to the printer. For example, when you print a document from within an application, the document data is spooled to a temporary storage area while the printer warms up. As soon as the printer is ready to print the document, the data is sent from the spool to the printer and the document is printed.

Semaphore:-

Semaphores are commonly use for two purposes: to share a common memory space and to share access to files. Semaphores are one of the techniques for interprocess communication (IPC). The C programming language provides a set of interfaces or “functions” for managing semaphores.
In programming, especially in Unix systems, semaphores are a technique for coordinating or synchronizing activities in which multiple processes compete for the same operating system resources. A semaphore is a value in a designated place in operating system (or kernel) storage that each process can check and then change. Depending on the value that is found, the process can use the resource or will find that it is already in use and must wait for some period before trying again. Semaphores can be binary (0 or 1) or can have additional values. Typically, a process using semaphores checks the value and then, if it using the resource, changes the value to reflect this so that subsequent semaphore users will know to wait.

Swapping:-

Swapping concept comes in terms of process scheduling. Swapping is basically implemented by Medium term scheduler.Medium term scheduler removes process from CPU for duration and reduce the degree of multiprogramming. And after some time these process can again be reintroduced into main memory. Process execution will again be resumed from the point it left CPU. This scheme is called swapping. More generally we can say swapping is removing of process from memory to secondary memory and again back to main memory.

Paging:-

Paging is a memory management technique in which the memory is divided into fixed size pages. Paging is used for faster access to data. When a program needs a page, it is available in the main memory as the OS copies a certain number of pages from your storage device to main memory. Paging allows the physical address space of a process to be noncontiguous.

Segmentation:-

Segmentation is one approach to memory management and protection in the operating system. It has been superseded by paging for most purposes, but much of the terminology of segmentation is still used, “segmentation fault” being an example. Some operating systems still have segmentation at some logical level although paging is used as the main memory management policy.

Thrashing:-

Thrashing is computer activity that makes little or no progress, usually because memory or other resources have become exhausted or too limited to perform needed operations. When this happens, a pattern typically develops in which a request is made of the operating system by a process or program, the operating system tries to find resources by taking them from some other process, which in turn makes new requests that can’t be satisfied. In a virtual storage system (an operating system that manages its logical storage or memory in units called pages), thrashing is a condition in which excessive paging operations are taking place.
A system that is thrashing can be perceived as either a very slow system or one that has come to a halt.
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Paging is a memory management technique in which the memory is divided into fixed size pages. Paging is used for faster access to data. When a program needs a page, it is available in the main memory as the OS copies a certain number of pages from your storage device to main memory. Paging allows the physical address space of a process to be noncontiguous.

Segmentation:- Segmentation is one approach to memory management and protection in the operating system. It has been superseded by paging for most purposes, but much of the terminology of segmentation is still used, “segmentation fault” being an example. Some operating systems still have segmentation at some logical level although paging is used as the main memory management policy.
Thrashing:- Thrashing is computer activity that makes little or no progress, usually because memory or other resources have become exhausted or too limited to perform needed operations. When this happens, a pattern typically develops in which a request is made of the operating system by a process or program, the operating system tries to find resources by taking them from some other process, which in turn makes new requests that can’t be satisfied. In a virtual storage system (an operating system that manages its logical storage or memory in units called pages), thrashing is a condition in which excessive paging operations are taking place.

A system that is thrashing can be perceived as either a very slow system or one that has come to a halt.

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