startnoden

Startnoden, literally the start node, is a term used in graph theory and network analysis to denote the designated initial vertex from which a process begins. In many contexts it is equivalent to the source node or root of a structure.

In graph traversal, the start node serves as the starting point for algorithms such as breadth-first search and depth-first search. From the start node, the algorithm explores adjacent vertices and continues outward, often marking visited nodes to avoid repetition. The choice of start node can influence the order of exploration and, in some cases, the performance of the algorithm.

In shortest-path problems, the start node is the source from which distances to all other vertices are computed. Algorithms like Dijkstra’s or Bellman–Ford determine the minimum distance from the start node to every reachable node, and may also record the preceding node to reconstruct paths.

For tree structures, the start node is typically the root, from which all other nodes branch. Rooted trees use the start node as a reference point for traversal and hierarchical organization.

In network design and process modeling, the start node often represents the origin of a flow or signal. Some models allow multiple start nodes (multi-source), reflecting simultaneous initiation points.

Practical considerations include how the start node is labeled, identified, and equipped with metadata such as coordinates, weights, or initial conditions. The selection of a start node can affect interpretation and results in simulations and analyses, although in many algorithms the node chosen as start does not alter the final reachability.

See also: source node, root, graph traversal, Dijkstra’s algorithm, BFS, DFS.