Stand-alone
It is called stand-alone for the mode that when two or more boards are used synchronously, the master and the slave are used independently without using synchronous signal lines.
Master
When two or more boards are used synchronously with synchronous control connector (SC connector), the board that outputs the signal to synchronous signal lines is called master.
Slave
When two or more boards are used synchronously with synchronous control connector (SC connector), the board works by inputting the trigger signal from synchronous signal lines is called slave.