Condos are typically a building where all the units in it are owned by their respective tenants.
Apartments are typically a building owned by a Company that rents out all the units, so none of the tenants have any ownership of the place they reside in.
If you ask if building condos is hard does that mean you think building apartments instead is easier, for example.
“High rise condo” May sound overly specific but it’s just the most common example of a category for which we don’t have a convenient descriptor.
EDIT: That applies to England and Wales (and Northern Ireland?) I believe the law is different in Scotland.
A block of apartments is just a grid of rooms/apartments with nothing else
But if you own and maintain the roof and exterior of your place up to the place where it adjoins to other units, then it's actually a townhome.