  Helioseismology has produced unprecedented measurements of the Sun's internal
structure and dynamics over the past 25 years. Much of this work has been based
on global helioseismology. Now local helioseismology too is showing its great
promise. This review summarizes very briefly the principal global results that
may be relevant to an understanding of the origins of solar magnetism. Recent
results regarding the variation of frequencies over the solar cycle and the
temporal variations of subsurface flows are briefly summarized.
