  Frank Harary introduced the concepts of sum and integral sum graphs. A graph
$G$ is a \textit{sum graph} if the vertices of $G$ can be labeled with distinct
positive integers so that $e = uv$ is an edge of $G$ if and only if the sum of
the labels on vertices $u$ and $v$ is also a label in $G.$ An \textit{integral
sum graph} is also defined just as sum graph, the difference being that the
labels may be any distinct integers. In this survey article, the authors bring
out several properties of sum and integral sum graphs obtained by different
authors.
