<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> Process management is an integral part of any modern - day operating system (OS). The OS must allocate resources to processes, enable processes to share and exchange information, protect the resources of each process from other processes and enable synchronization among processes . To meet these requirements, the OS must maintain a data structure for each process, which describes the state and resource ownership of that process, and which enables the OS to exert control over each process . </P> <P> In many modern operating systems, there can be more than one instance of a program loaded in memory at the same time . For example, more than one user could be executing the same program, each user having separate copies of the program loaded into memory . With some programs, it is possible to have one copy loaded into memory, while several users have shared access to it so that they each can execute the same program - code . Such a program is said to be re-entrant . The processor at any instant can only be executing one instruction from one program but several processes can be sustained over a period of time by assigning each process to the processor at intervals while the remainder become temporarily inactive . A number of processes being executed over a period of time instead of at the same time is called concurrent execution . </P>

What is a process manager in operating system
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