about cronus database

hi, i just download nav 2013 R2 and still a newbie.

when i log in to NAV, the Nav ask a server name and password. my friend in my company tell me the pass is ******* and the server is ***** and in cloud. 

I am wondering now, how about if i want to use cronus database.. ?  

should i install sql server in order to work with cronus ?

please forgive my ignorance if this question is so silly.. 

thanks