*  Some of the widely used operating systems are as follows:-    1. Batch operating system.    2. Time-Sharing oprtaing system.   3. Distributed operating system.   4. Network operating system.   5.  Real-Time operating system. 1> Batch Operating System:-                 This type of operating system does not directly interact with computer system. Each user prepares job on an offline device such as punch card and submmits to the computer operator.   There is an operator which takes similar jobs having same requirement and group them into batches. * Advantages of Batch Operating System:-   Repeated jobs are done fast in batch systems without user interaction.   You don’t need special hardware and system support to input data in batch systems.   Best for large organizations but small organizations can also benefit from it.   Batch systems can work offline so it makes less stress on processor.   The idle time batch system is very less.  Multiple users can share

 An operating system is a system software which acts as an interface between a computer user and computer hardware. The purpose of an operating  system is to provide an environment in which a user can execute  programs in a convenient and efficient manner. Since  an operating system is large and complex, it must be created  piece by piece. Each of these pieces should be a well-delineated portion of the  system, with carefully defined inputs, outputs, and functions. Ex:- Unix, Linux, MS Dos, macOS, windows, android etc.   *   Important functions of an operating System:-   1>  Memory Management.   2>  Processor Management.   3>  Device Management.   4>  File Management.   5>  Security providing.   6>  Job accounting.   7>  Control over system performance.   8>  Error detection.   9>  Coordination between other softwares. 1. Memory Management:-   The operating system manages the Primary Memory or Main Memory.  An operating system 

                       LINKED LIST    A linked list is non-premitive data structure.  A  linked list  is a way to store a collection of elements. Like an array these can be character or integers. Each element in a linked list is stored in the form of a  node .   And a node is a collection of two sub-elements or parts , information or data part and another is address part .  A linked list is formed when many such nodes are linked together to form a chain. Each node points to the next node present in the order. The first node is always used as a reference to traverse the list and is called  Start or head and t he last node points to   NULL . Arrays can be used to store linear data of similar types, but arrays have some limitations as the size of the arrays is fixed: So we must know the upper limit on the number of elements in advance. Also, generally, the allocated memory is equal to the upper limit irrespective of the usage. Inserting a new element in an array of elem