What is the difference between a studio and an apartment?

Studios:

A studio consists of a single living space where you sleep. The size determines whether the studio is suitable for 1, 2, 3, or sometimes 4 people. Every studio includes a bathroom with a shower or bath and a toilet. Additionally, each studio is equipped with a kitchenette, which typically includes electric hobs and a fridge.

Apartments:

An apartment always has at least two separate rooms: a bedroom and a living room, which can also serve as a living and sleeping area.

Types of apartments:

2-room apartment = 1 bedroom + living room

3-room apartment = 2 bedrooms + living room

Etc.

Every apartment includes a bathroom with a shower or bath and a toilet. Each apartment also has a kitchenette with electric hobs and a fridge.