License question

[prashant sinha]

Hello There,I am looking to install PostgreSQL on a Microsoft Azure cloud VM 
for a product I am developing for business purpose. Is there a free version of 
PostgreSQL available which I can use without buying any licenses? In case I 
want to self install and manage the database? Just need guidance if I can 
install the available version from site for business purpose too or I must buy 
licenses? Will appreciate an appropriate related answer.
Thanks,Prashant