In mathematics, a source is an part of a larger structure to which values "flow out of," either locally or globally, upon iteration, traversal, etc.

For example, a digraph sink is a node of a directed
graph with no entering edges.

The opposite of a source is a sink.

## See also

Digraph Source,

Sink
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## Cite this as:

Weisstein, Eric W. "Source." From *MathWorld*--A
Wolfram Web Resource. https://mathworld.wolfram.com/Source.html