Software consists of computer programs, which are sequences of instructions for the computer. The process of writing (or coding) programs is called programming, and someone who performs this task is called a programmer. The computer cannot do anything until it receives instructions from the software. Although computer hardware is, by design, general purpose, a platform that allows the user to instruct a computer system to perform various functions that meet needs. Software is a collection of programs or a sequence of instructions given to change the state of your computer's hardware in a certain way. 15.2.1 System software System software is the class of programs that control and support the computer system and its information processing activities. System software also facilitates programming, testing, and debugging of computer programs. It is much more powerful or efficient than application programs and is usually independent of any type of required software program applicationSystems helps support application software that runs on it as per the user's directions. For example, when the computer is turned on, the system initialization program (an operating system program) prepares and prepares all devices for processing. 15.3 System Control ProgramsSystem control programs help control the activities of hardware, software, and various data. sources of a computer system. The main control program of the system is the operating system. The operating system controls the overall functioning of the computer, including monitoring or controlling the state of the computer and scheduling operations, which include input and output processes. Additionally, the operating system allocates the CPU the necessary time and main memory for programs...... middle of the paper ...... for concurrent or concurrent processing with a CPU.15.3.4 Virtual MemoryThe memory virtual distributes the entire application program or a module into fixed-length portions called pages. Virtual memory creates more main memory than actually exists in the computer system. It allows a program to behave as if it had access to the entire storage capacity of a computer, rather than just the amount of primary memory installed on the computer. The system executes some pages of instructions while extracting others from secondary memory. In effect, primary memory is extended into a secondary storage device, allowing users to write programs as if primary memory were larger than it actually is. This expanded capacity increases the computer's speed and allows it to efficiently execute programs with very large numbers of instructions. 15.3.5 Fault Tolerance