Divide a big block into several small blocks, each small block is not connected, but the small blocks are connected internally, and each small block is a connected branch of the big block.

For a connected graph, after all the elements of the point cut set are deleted, the graph is disconnected, but if only the proper subset of the point cut set is deleted, the graph is still connected. Edge cut sets are similar to point cut sets.

This is my understanding of these things, I hope I can help you!