The three types of operating systems divided by application areas are (), server operating system and (), where server operating system stock refers to the operating system installed on the mainframe computer, such as Web server, application server and database server, etc. (Multiple Choice)

The three types of operating systems divided by application areas are (), server operating system and (), where server operating system stock refers to the operating system installed on the mainframe computer, such as Web server, application server and database server, etc. (Multiple Choice)
A . Open source operating system
B . Embedded operating system
C . Desktop operating system
D . Smart card operating system

Answer: BC