Utility Workers Union of America
AFL - CIO Local 127

The heart and soul of any union is its members, and they are pulled together by a network of first-line union representatives, often called stewards.  Your union may use a different title for this position, such as department rep or representative spokesperson, but the functions will be the same.  Stewards are the “eyes and ears” of the union, keeping track for the union of what’s happening on a day-to-day basis.  An effective steward functions as a two-way pipeline:  passing information along to higher-ups in the union, so that they can formulate plans to respond to employer actions, and making sure that the union members in their areas are kept informed about what’s going on within the union.
—Adapted from The Union Member's Complete Guide, by Michael Mauer