Detailed description of operating system categories

The operating system can be classified according to different methods. For example, the number of users can be divided into single-user and multi-user systems. Based on the hardware scale on which the operating system depends, it can be divided into mainframe, middleware, minicomputer and minicomputer operating systems; according to the operating system's work environment provided to the user, it can be divided into single-user operating systems, multi-channel batch processing operating systems, time-based operating systems, real-time operating systems, network operating systems and distributed operating systems. 1. Single/multi-user operating systems A single user's operating system can only run one user's process at a time. Compared with a multi-user operating system, a single user can log on to multiple users simultaneously and run processes of multiple users, for example, Win XP itself is a multi-user operating system. both local and remote support allows multiple users to log on simultaneously. It provides users with an online interactive working environment, such as MS-DOS, which is a typical single-user operating system. Features: single user, no high utilization, good interaction Ii. Batch Processing System A batch processing system can be divided into a simple batch processing system and multiple batch processing systems. Multi-channel batch processing system is multi-channelProgramThe basic idea of combining the design technology with the batch processing system is to submit a batch of reasonably matched jobs to the operating system through the input device each time, and temporarily store them in the external storage for operation. When the system needs to call a new job, according to the current running situation and user requirements, according to a certain debugging principle, select one or more jobs from the external memory and load them into the memory for operation. The user uses the control command to describe the specific arrangement for each step of the job, and hand over the control together with the program and data as a job to the operating system. Therefore, users are not allowed to interact with their jobs during system operation, that is, users cannot directly intervene in the running of their jobs until the job is completed.
Multi-channel batch processing systems are generally used in large computer systems and require high utilization and throughput. For example, OS/360 MTV is a typical multi-channel batch processing operating system.
Batch Processing Operating System: organize jobs in batches and input all the descriptions and content of the job into the computer at a time. The computer runs the jobs in sequence, the user shall not intervene in the running of the program within the range of one batch. It is an offline processing system without user intervention. It is suitable for computing centers dedicated to computing services and can help users complete large-scale engineering operations.

Single-channel program: stores only one batch of programs or one program in the primary memory. When the CPU runs the program and a certain waiting condition occurs, the CPU stops running the current program, the CPU remains idle until the waiting conditions are met. Multi-program: stores several user jobs in the primary storage at the same time, allowing these jobs to run cyclically in the system. When the CPU runs a program for conditional waiting, you can switch to another program to run another job in the system. Features: user intervention is not allowed, no interaction, and the utilization rate of a single batch processing system is lower than that of multiple batch processing systems. Iii. Time-Sharing System The time-sharing system is developed on the basis of multiple batch processing systems. In the time-sharing system, you can use computer interaction sessions to control the operation of jobs online, A time-sharing system can contain dozens or even hundreds of terminals. Each user can operate or control jobs on his/her own terminal. From a macro perspective, multiple users can work simultaneously, share System Resources. From a micro perspective, each process runs in turn by time slice, improving the utilization of system resources. Ctss is the earliest time-based operating system, and UNIX is a widely used time-based operating system. Features: multi-user, interactive Iv. Real-Time System A real-time system refers to the computer's rapid response to a specific input to control the objects that send real-time signals, that is, the computer responds to external event requests in a timely manner and completes the processing of the event within a specified short time, and control all real-time devices and real-time task coordination to the ground. For example, in missile flight control, industrial process control, and various ticket booking businesses, a computer system is required to immediately respond to user requests. A real-time system is an operating system suitable for such environments. It is divided into real-time process control system and real-time information processing system. Features: good real-time performance V. General operating system The general operating system is generally above Integration of three operating systems. For example, when a batch processing system is combined with a time-sharing system, the system responds in a timely manner when there is a time-sharing user in the system; when the system does not have a time-sharing user or a small number of time-sharing users, or to handle less urgent Batch jobs, in order to improve the system's resource utilization. In this system, time-based jobs are called foreground jobs and batch jobs are called background jobs. Similarly, the batch processing system is combined with the real-time system. When real-time task requests exist, the batch processing is performed in real time, and the real-time system is called, batch Processing is called the backend. Vi. Network Operating System Network operating systems are a collection of software and related procedures (such as protocols) that allow computers on the network to conveniently and effectively share network resources and provide various services to network users. The network operating system provides the most basic core functions required for network operations, such as the Network File System, memory management, and process task scheduling. Network service programs run in the network operating system software. Each computer uses communication software to establish communication between the network hardware and other computers. Communication Software also provides supported communication protocols to send requests or responses over the network. VII. Distributed Operating System With the development of the programming environment, man-machine interface and software engineering, a distributed computer system composed of several computers connected by high-speed LAN has emerged, and the corresponding operating system needs to be configured, that is, the distributed operating system. A Distributed Computer system is similar to a computer network. A Distributed Computer system connects an independent data processing system or computer system through a communication network to achieve information exchange, resource sharing, and collaborative tasks.
The distributed operating system is still in the research stage, and there is no practical system yet.