The operating system is a program that manages computer hardware and software resources, and is also the kernel and cornerstone of the computer system. The operating system is a huge management control program, which includes five aspects of management functions: process and processor management, job management, storage management, device management, and file management.

①Microsoft Windows：Windows uses a graphical mode GUI, which is more user-friendly than the way DOS used to type commands.

②Linux： It is a multi-user, multi-tasking, multi-threaded and multi-CPU based operating system based on POSIX and UNIX. It can run major UNIX tools, applications and network protocols.

③Android：Android is a Linux-based free and open source operating system. Mainly used in mobile devices such as smartphones and tablets, led and developed by Google and the Open Handset Alliance.

④iOS：Apple first announced the system at the Macworld conference on January 9, 2007, originally designed for the iPhone, and later applied to iPod touch, iPad and Apple TV.