Technically, it’s most floors, for example the upper floors in a house are ‘timber suspended’ in that they’re made from joists with floorboards on top but in this case I was referring to a ‘raised floor’.
Most commercial buildings are built with concrete floors of one type or another and then they fit a secondary floor above, this is the bit you walk on. There is a void between the two ‘floors’ and this void is used for all the cables for phones, computers, electricity etc.
Like this
View attachment 72436