Absolute values and their completions - like the p-adic number fields-
play an important role in number theory. Krull's generalization of
absolute values to valuations made applications in other branches of
mathematics, such as algebraic geometry, possible. In valuation theory,
the notion of a completion has to be replaced by that of the so-called
Henselization.
In this book, the theory of valuations as well as of Henselizations is
developed. The presentation is based on the knowledge aquired in a
standard graduate course in algebra. The last chapter presents three
applications of the general theory -as to Artin's Conjecture on the
p-adic number fields- that could not be obtained by the use of absolute
values only.