Hi,

In life sciences one studies in detail about the living things and process occuring to them and their origin, physiology etc.

In earth sciences one studies about the physical and chemical process occuring on earth and in atmosphere ,their impact and interrelationships with one another.

CSIR NET exam is divided into following subjects -

Chemical sciences- masters course in chemistry

Physical sciences - masters of science course in physics

Life sciences - masters of science  course in botany, zoology and like subjects

Earth, Atmospheric, Ocean and Planetary Sciences-

Masters course in Geology, geochemistry etc. That is masters in all  the subjects which comes in this stream.