I can see why you're confused
@hollydolly - The term condominium
does not refer to a type of building structure. The term condominium or "condo" refers to
a type of ownership. The structure itself can be a highrise apartment building or a grouping of townhouses (usually one, two or three story houses joined to each other).
In all condos, regardless of the building structure, people own their living unit AND they as a group of owners jointly own the "common areas" within the apartment or townhouse complex. These common areas would include; roadways, parking areas, pools or tennis courts etc. As such, every owner pays a monthly fee for the operation and maintenance of all "common areas" within the complex. In the case of highrise buildings, common elements would include elevators & underground parking areas - anything that all owners have a right to use.
In Canada at least, the condominium is goverened by an elected board of governers (I believe in the US they refer to it as an HOA) who are also owners of at least one condo unit within the complex. The board of governors sets the annual financial budget for the operations of the condo corporation, including a reserve fund for major repairs that are considered to be over & above monthly maintenance and they set the rules governing what owners can and can't do to the exterior area of their owned unit.
Hopefully that gives you a better idea of what the term condominium means. I'm guessing it's similar to your place in Spain. You own the living quarters and you, plus all the other unit owners, pay a monthly fee for someone to manage everything else in & around the complex that's used by all owners & their guests.