[masklinn]

Directed Acyclic Graph.

Graph = graph, a structure composed of a set of objects (nodes or vertices) with links between them (edges).

Directed = the edges have an orientation / a direction.

Acyclic = there's no cycle, you can't come back to a node (in a directed graph you have to follow edge direction).

In Git, the commit objects are nodes, the "parent" link(s) is a directed edge, and because commit objects are immutable you can't create a commit which refers to one of its "descendants" and thus the graph is acyclic.