Operating system is the interface between users and computers, and also the interface between computer hardware and other software. The functions of the operating system include managing the hardware, software and data resources of the computer system, controlling the program running, improving the man-machine interface, providing support for other application software, making all the resources of the computer system play their roles to the maximum, providing various forms of user interfaces, enabling users to have a good working environment and providing necessary services and corresponding interfaces for the development of other software.
In fact, users don't need to touch the operating system. Operating system manages computer hardware resources, and allocates resources according to resource requests of application programs, such as dividing CPU time, opening memory space, calling printers, etc.
: Typical system
Operating system UNIX
UNIX is a powerful multi-user and multi-task operating system, which supports multiprocessor architecture. According to the classification of operating system, it belongs to time-sharing operating system. UNIX was originally created by Ken Thompson and Dennis Ritchie at 1969 in the development of Bell Labs at&T.
Unix (Unix-like operating system refers to all kinds of traditional Unix and all kinds of systems similar to traditional Unix. Although some of them are free software and some are commercial software, they all inherit the characteristics of the original UNIX to a certain extent, have many similarities, and all abide by POSIX specifications to a certain extent. Unix-like systems can run under a variety of processor architectures, and have a high utilization rate on server systems, such as workstations in universities or engineering applications.
Operating system Linux
Linux-based operating system is a multi-user and multi-task operating system introduced by 199 1 in the 20th century. It is fully compatible with UNIX. Linux was originally a kernel program of a UNIX-based operating system developed by Linus Torvalds, a computer student at Helsinki University in Finland. Linux is designed to be used more effectively on Intel microprocessors. Later, at the suggestion of richard stallman, it was released under the GNU General Public License and became a Unix variant of free software. Its biggest feature is that it is a free and open source operating system, and the open source code and kernel source code can be freely disseminated.
After several years of efforts, the free and open source Linux system gradually encroaches on the professional field of patented software. For example, the IRIX system of ──SGI, a computer animation giant, has been replaced by Project No.9 and Inferno system designed by Linux family and Bell Labs R&D team, which are both used in distributed expression environment. Unlike other Unix systems, they choose to bring their own graphical user interface. Plan 9 is not popular because it was not free software when it was first introduced. Linux has various distributions, usually GNU/Linux, such as Debian (and its derivative systems Ubuntu, Linux Mint), Fedora, openSUSE and so on. Linux distribution, as a personal computer operating system or server operating system, has become the mainstream operating system on the server.
Operating system Mac OS X
Mac OS is an operating system running on Apple Macintosh series computers. Mac OS is the first successful graphical user interface in the business field. The Macintosh team includes Bill Atkinson, Jeff Ruskin and andy hertzfeld. Mac OS X was first introduced in shopping centers on 200 1. It consists of two main parts: Darwin, which is a Unix-like open source environment based on BSD source code and Mach microkernel.