What's the difference between leasing an apartment and having a rental contract?

Yes, interchangeable.

Er, almost, but having a lease generally means that the rental contract is for a period longer than one month.

In general, either you are “renting month to month”, meaning the rental contract says you might choose to leave (or that the owner might raise the rent) at any time, with no penalty or obligation, or alternatively you “have an X month (or year) lease”, meaning that you agree to rent it for some number (X) of months, and the party renting it to you agrees to let you rent it for a fixed amount. If you have a lease but want to stop renting sooner, the contract may specify a penalty, for instance that you still have to pay until someone else rents the apartment. Also it is common in many places for a rental contract to specify a lease period but after that period (often one year), the contract becomes a month-to-month rental unless the renter elects to renew the lease for another year.

In both cases, there is a rental contract, but “lease” typically implies a period of fixed conditions longer than a month.

When you lease, the one you are leasing from is responsible if you fail to pay , do damage etc.

Right @Zaku ‘s answer.

A “lease” usually means you are committing to more than a month to month rental agreement. I once leased a home and it was on a 2 year lease, meaning that the 2 year contract was not to be broken without penalty.

You just go by the contract, don’t worry about whether it is called a lease or a rental agreement, the two are used interchangeably all too often in common every day use. All that matters is what the contract says, the specifics of what you are agreeing to in terms of how many months, payment, move in date, when the rent is due each month, etc.

If you don’t have a contract, which I don’t recommend, but if you don’t, then you are basically month to month and you or the landlord have to give notice in writing if you are going to leave or he is asking you to leave. Some states it is 15 days notice, others 30 days notice.

The terms can be interchangeable, but often, if a lease is not mentioned they might be referring to a month to month agreement.

@flo, I think you are thinking about a sub lease.