reproducing KERNEL HILBERT SPACES ARISE IN A NUMBER OF AREAS, INCLUDING APPROXIMATION THEORYS STATISTICS, MACHINE LEARNING THEORY, GROUP REPRESENTATION THEORY AND VARIOUS AREAS OF COMPLEX ANALYSIS. IN THIS TALK THE reproducing KERNEL HILBERT SPACES ARE INTRODUCED AND THEIR GENERAL PROPERTIES ARE INVESTIGATED.FOR BETTER UNDERSTANDING OF THESE SPACES SOME EXAMPLES ARE GIVEN. MOREOVER, IN THIS SPACE, A SAMPLING FORMULA IS INTRODUCED, WHICH IS AN EXTENSION OF A FAMOUS FORMULA KNOWN AS THE PALEY-WIENER (PW) OF BAND-LIMITED SIGNALS. IN PARTICULAR, A SINGLE CHANNEL SAMPLING FORMULA IS DISCUSSED.