What is a tenant? The person who rents a home under a lease and has the legal right to occupy it, with duties to the landlord set by the lease and by state law.
A tenant holds a tenancy: the right to possess and use a property that belongs to somebody else, for a period and in exchange for rent. The lease creates it and state landlord and tenant law fills in whatever the lease does not say and overrides whatever it says wrongly. In Nevada that law is NRS chapter 118A, and it gives every tenant rights the lease cannot remove: a habitable home, notice before the landlord enters, the return of the deposit with an itemization, and a court process before any eviction.
The word matters at the edges. A guest who stays long enough can become a tenant with those rights, which is why leases limit guests. A roommate on the lease is a tenant with the same rights and the same liability for the whole rent; one not on the lease is the leaseholder's guest or subtenant. A tenant at will has no fixed term and can be ended with the state's notice; a tenant at sufferance stayed past the end of a lease and can be evicted.
Tenants also owe things: the rent on time, reasonable care of the home, no damage beyond normal wear, and access for repairs on proper notice. The security deposit is the landlord's protection for the last three.
A worked example
Two friends sign a twelve-month lease at $1,900 together. Both are tenants, and both owe the whole $1,900: when one moves out in month seven, the landlord can collect the full rent from the one who stayed, and it is between the two friends to settle it.
See what a lease makes a tenant responsible for
Questions people ask
What is the difference between a tenant and an occupant?
A tenant signed the lease and holds the tenancy, with its rights and its liability for the rent. An occupant lives there under the tenant, such as a child or a guest, and has no direct contract with the landlord.
When does a guest become a tenant?
When they have lived there long enough, contributed to rent, or received mail there, depending on the state and the lease. Most leases cap guest stays at one or two weeks to keep the line clear.