Hi, If you want to buy a salon as a going concern then you'll have to buy the business and the remainder of the lease and then pay rent.
If you want to buy an empty shop and start your own salon, then you can just rent (i think) or buy the lease and rent.
A lease is really just a very complicated contract between you and your landlord, but without one you'll never, really, have any rights to the property. You wont have the same security and you wont have a business to sell, should you wish to in the future.
I got a 10 year lease, with a 3 year break clause (in my favour), radius clause, rent review every 3 years etc etc
HTH
jes