At present, there is no global standard plug and socket. Usually, three types of plugs are used most – Flat Plug System, Square Plug System and Round Plug System.
Flat Plug System: It is raised by American National Standards Institute, mainly used in Asia and North America, such as United States, Canada, Japan, South Korea and China, etc.
Square Plug System: It is raised by British Standard Institute, mainly used in Oceania and South Africa, such as United Kingdom, Singapore, Australia, India and Pakistan.
Round Plug System: It is raised by International Electrical Equipment Certification Committee, mainly used in Europe, like France, Italy, Spain, Switzerland, Sweden and more countries.