An outer-1-planar graph is a graph admitting a drawing in the plane so that
all vertices appear in the outer region of the drawing and every edge crosses
at most one other edge. This paper establishes the local structure of
outer-1-planar graphs by proving that each outer-1-planar graph contains one of
the seventeen fixed configurations, and the list of those configurations is
minimal in the sense that for each fixed configuration there exist
outer-1-planar graphs containing this configuration that do not contain any of
another sixteen configurations. There are two interesting applications of this
structural theorem. First of all, we conclude that every (resp. maximal)
outer-1-planar graph of minimum degree at least 2 has an edge with the sum of
the degrees of its two end-vertices being at most 9 (resp. 7), and this upper
bound is sharp. On the other hand, we show that the list 3-dynamic chromatic
number of every outer-1-planar graph is at most 6, and this upper bound is best
possible.