The 103 series is a national railway standard commuter type DC train that started mass production in 1964 and has manufactured more than 3,400 cars for more than 20 years. It is active in DC line sections all over the country, and there are many variations depending on the manufacturing time and line section used, and a small number are still in operation. It is a commuter train that is familiar not only to railroad fans but also to many people.