3 bedroom apartments generally have a combined living/dining area with a separate kitchen and bathroom; multi bedroom apartments may sometimes have ensuites attached to the main bedroom. Internal laundries are generally a common feature - especially in more modern apartments.
The more bedrooms an apartment has will generally be proportional to the amount of rent you pay, for example a 1 Bedroom apartment with the same sized living space as a 3 bedroom apartment, located in a similar area would have a great difference in price. Many young people choose to rent larger apartments - which although on surface value may look more expensive than a smaller apartment, when the rent is divided amongst 3-4 people it is quite affordable.