The internal and external sense bases together form the "six sense bases." In this description, found in texts such as Salayatana samyutta, the coming together of an object and a sense-organ results in the arising of the corresponding consciousness.
The Mahayana developed out of the traditional schools, introducing new texts and putting other emphases in the teachings, especially sunyata and the Bodhisattva-ideal.
[S]ome of the details of tantric iconography are developed from abhidharma [that is, in this context, detailed analysis of the aggregates]. Different colors and feelings of this particular consciousness, that particular emotion, are manifested in a particular deity wearing such-and-such a costume, of certain particular colors, holding certain particular sceptres in his hand. Those details are very closely connected with the individualities of particular psychological processes.