Usually preformed concrete is brought in and stacked by crane like Legos. They are mortared and plastered together.
Floors between are also precast concrete. You can see there are pipes laid in the panels to be used as conduits for plumbing and electrical.
The walls are typically triple courses of common brick, though sometimes concrete blocks are used.
After the exterior walls are up, the roof is built without pre-made trusses.
The exterior walls of better-constructed buildings are covered with a shell layer of insulation and then there may be an additional course of bricks or plaster. Sometimes they are just plastered without insulation.This same method is used for single homes and apartments or multi-story buildings. High-rise apartment/commercial buildings use more poured concrete, though the walls between floors are usually laid brick/block.
Interior walls are also 3 bricks thick. Grooves are chiseled out for electrical conduits to be embedded in the plaster coat which is about 1" thick.
Roofs are typically tile which is more expensive or they may be corrogated metal or asphalt.
It is obvious that many people begin living in homes and continue to work on them over years of time. We sense that they do things as they have money and time, not going into debt. This home has been "in progress" since we arrived 2 years ago. Building the fence is the new addition."Finished" apartment buildings are only rough on the interior. The renter or buyer of an apartment must add the plumbing, electrical, cabinets, wall and floor coverings themselves. Only bare walls and a main electrical box are provided.