Sometimes boundaries are based on linguistic differences, but this may be coincidental.
As to differences of style, regularities of form and tradition do occur such that it is possible to attribute particular African art objects to particular places, regions, or periods.
Thus, some African art has value as entertainment; some has political or ideological significance; some is instrumental in a ritual context; and some has aesthetic value in itself.
That this happened is understandable, given the demands of colonial administration, but this historical contingency cannot help in understanding the dynamic of stylistic variation in Africa.
The second is technology, in that in some areas differences of style depend on the material employed.
The third is individuality, in that an expert can identify the works of individual artists; inability to do so usually derives from a lack of familiarity.
Some further general points can be made, however, in regard to the status of precolonial sub-Saharan art.
First, in any African language, a concept of art as meaning something other than skill would be the exception rather than the rule.