What is common in a school master and a station master?

Master has lots of meaning.
Master means one who control over another and directs other. Station master controls the other station employees for the efficient running of the station.
Master also means male teacher. In that red colour is common.

School master deals with students and education whereas station master deals with passengers and train journey. School master works at school and station masters at Railway stations. In both the locations, bell sound plays a vital role. School master works on black boards and station master works on signal posts. School master can create several station master. But station master cant create school masters.

May be 'Master' is the common in both.. :D

Both needs to work hard to keep all the things managed.. May be that;s the common.

master is the common in school master and station master

Master is common and both have responsible jobs.