Its original sense as a mathematical term defines this word most accurately. When a given space is closed&sbquo an element is defined as to whether it is compact or not in relation to another finite element in the whole of this closed space (called a closet set). By outlining its mathematically conclusive definition colloquially&sbquo its original meaning&sbquo comprising COM = together and PACT = tighten hard&sbquo becomes clear. It is evident that the word expresses densely packed elements or a state in which things are packed tight in a small closed space. In general&sbquo it means a smaller volume that is packed with concentrated contents. In design&sbquo the phrase "compactness as a concept" means conserving space as much as possible to realize&sbquo both rationally and functionally&sbquo superior performance within a spatially condensed package. In order to establish compactness&sbquo it will be necessary to realize spatial condensation itself&sbquo in other words the constituent elements must secure certain qualities of density and closure as their structure. In terms of technological concentration or condensed packaging&sbquo demand for compactness should rise future. To understand compactness here&sbquo it's necessary to return to the mathematical definition of compact space. This is because technological compactness is aiming for a concentration of technology that can no longer be detected visually&sbquo as with nanotechnology. Compact design has become a timely demand.