  It is often argued that {\it all the information of a gravitational theory is
encoded in the surface term of the action}; which means one can find several
physical quantities just from the surface term without incorporating the bulk
part of the action. This has been observed in various instances; e.g.
derivation of the Einstein's equations, surface term calculated on the horizon
leads to entropy, etc. Here I investigate the role of it in the context of
entropy function and entropy of extremal near horizon black holes. Considering
only the Gibbons-Hawking-York (GHY) surface term to define an entropy function
for the extremal near horizon black hole solution, it is observed that the
extremization of such function leads to the exact value of the horizon entropy.
This analysis again supports the previous claim that there exists a ``{\it
holographic}'' nature in the gravitational action -- surface term contains the
information of the bulk.
