Subgraph presence refers to the existence of a smaller graph, known as a subgraph, within a larger graph. In graph theory, a subgraph is formed by a selection of vertices and edges from the original graph, maintaining the connections between the selected vertices. This concept is important for analyzing complex networks, as it helps identify patterns and relationships within the data. Detecting subgraph presence can be useful in various fields, including computer science, biology, and social network analysis. For example, in social networks, identifying subgraphs can reveal communities or clusters of users with similar interests or behaviors, aiding in targeted marketing or information dissemination.