Pure science is primarily concerned with the development of theories establishing relations between the phenomena of the universe. These relations (hypotheses, models) become the working laws or principles of science.
Applied science, on the other hand, is directly concerned with the application of the working laws of pure science to practical affairs of life, and to increase man's control over his environment.
The study of radioactivity began as a piece of pure research, but its results are now applied in a great number of different ways- in cancer treatment in medicine, agriculture, in geology …etc. conversely work in applied science and technology acts as a direct stimulus to the development of pure science. Such an interaction occurs, For example, when the technologist reveals a gap or limitation in the theoretical model. Often further interaction occurs when the technologist provides the pure scientist with more highly-developed instruments by which he can undertake deeper researches.
It seems, then, that two branches of science are mutually dependent and interacting, and the so-called division between the pure scientist and the applied scientist is more apparent than real.