Explanation of minimal spanning tree

The table below shows the order in which nodes are added to the minimal spanning tree rooted at node 0. In each iteration, a new node is added to the tree, and the distance to that node from all nodes adjacent to it are updated. Refresh the page to see another randomly generated unweighted graph.

0123456789
0infinfinfinfinfinfinfinfinf
09infinfinfinfinfinfinfinf
0918infinfinfinfinf24
0918inf19139524
0918inf19139524
094319139524
094319139524
09431939524
09431939524
09431939524