Morphing is a term of computer science and it can be defined as a progressive transformation of one image into another by computer processing. Visual animation which consists of continuous transformation; one thus passes from an original image to a final image in different transitions. Morphing is often used with portraits.
The Future of Morphing
The main problem with morphing is that it is long and therefore expensive. Moreover, it is still quite unknown and a client will not necessarily ask you for it. This is why you rarely see morphing on sites. It is rather intended for portfolios or agency/company sites, to show its know-how.