The operating system can be roughly divided into 6 categories.
① simple operating system. It is the operating system configured at the beginning of the computer, such as IBM's disk operating system dos/360 and the microcomputer's operating system cp/m. This kind of operating system's function mainly is the operation command's execution, the file service, supports the high-level programming language compiling program and controls the external equipment and so on.
② time-sharing system. It supports multiple users at different terminals at the same time using a computer, independent of each other, users feel like a computer is all used by him.
③ real-time operating system. It is the operating system that is configured for real-time computer systems. The main feature is that the allocation and scheduling of resources must first consider real-time and then efficiency. In addition, the real-time operating system should have strong fault-tolerant ability.
④ network operating system. It is the operating system configured for the computer network. With its support, each computer in the network can communicate and share resources with each other. Its main characteristic is to complete the network communication task with the hardware of the network.
⑤ distributed operating system. It is the operating system configured for the distributed computing system. It differs greatly from other operating systems in terms of resource management, communication control and the structure of the operating system. Because the distribution of computer system resources distributed on different computer systems, the operating system on the user's resource requirements can not be as normal as the operating system to wait for resources directly to allocate the simple approach is to search the system on each computer, to find the required resources before they can be allocated. For some resources, such as files with multiple replicas, you must also consider consistency. Consistency refers to the fact that several users agree on the data that is read by the same file. To ensure consistency, the operating system must control the reading, writing, and operation of files so that multiple users can read a file at the same time, and at any one time only one user can modify the file. The communication function of distributed operating system is similar to network operating system. Because the distributed computer system does not resemble the network distribution very widely, simultaneously distributes the operating system also to support the parallel processing, therefore it provides the communication mechanism and the network operating system provides differs, it requests the communication speed to be high. The structure of distributed operating system is different from other operating systems, it is distributed on each computer of the system, it can deal with the various demands of users in parallel, and has strong fault-tolerant ability.
⑥ Intelligent Operating system.