т. граф. связный граф (граф, любые две вершины которого можно соединить цепью)
связный граф
A graph such that there is a path between any pair of nodes (via zero or more other nodes). Thus if we start from any node and visit all nodes connected to it by a single edge, then all nodes connected to any of them, and so on, then we will eventually have visited every node in the connected graph.