Gaussian processes can be viewed as a far-reaching infinite-dimensional
extension of classical normal random variables. Their theory presents a
powerful range of tools for probabilistic modelling in various academic
and technical domains such as Statistics, Forecasting, Finance,
Information Transmission, Machine Learning - to mention just a few. The
objective of these Briefs is to present a quick and condensed treatment
of the core theory that a reader must understand in order to make his
own independent contributions. The primary intended readership are
PhD/Masters students and researchers working in pure or applied
mathematics. The first chapters introduce essentials of the classical
theory of Gaussian processes and measures with the core notions of
reproducing kernel, integral representation, isoperimetric property,
large deviation principle. The brevity being a priority for teaching and
learning purposes, certain technical details and proofs are omitted. The
later chapters touch important recent issues not sufficiently reflected
in the literature, such as small deviations, expansions, and
quantization of processes. In university teaching, one can build a
one-semester advanced course upon these Briefs.