  The Standard Model of electroweak interactions has had great success in
describing the observed data over the last three decades. The precision of
experimental measurements affords tests of the Standard Model at the quantum
loop level beyond leading order. Despite this great success it is important to
continue confronting experimental measurements with the Standard Model
predictions as any deviation would signal new physics. As a fundamental
parameter of the Standard Model, the mass of the W-boson, M_W, is of particular
importance. Aside from being an important test of the SM itself, a precision
measurement of M_W can be used to constrain the mass of the Higgs boson, M_H.
In this article we review the principal experimental techniques for determining
M_W and discuss their combination into a single precision M_W measurement,
which is then used to yield constraints on M_H. We conclude by briefly
discussing future prospects for precision measurements of the W-boson mass.
