A net lease is any lease in which the tenant pays some or all property expenses in addition to rent.
Net leases come in single (N), double (NN), and triple (NNN) variations, depending on how many of the three major expenses the tenant pays: property taxes, insurance, and maintenance. The more the tenant takes on, the more predictable the landlord's income. That is why net leased properties appeal to investors who want passive ownership. The labels are not standardized, so the lease is the authority on who pays what.