What is a "Not Rented for Profit" rental?

[Joel Corrales]

I am renting a home to a friend of the family for far below rental market value. (Rent Zestimate®: $1,599 and I am collecting $600/month)

Can this be considered a "Not Rented for Profit" rental property/agreement?

If so, would this allow me to deduct rental expenses below the amount of your rental income?

Is there anything else that I would need to or want to know in managing this property?