The document discusses randomized graph algorithms and techniques for analyzing them. It describes a linear time algorithm for finding minimum spanning trees (MST) that samples edges and uses Boruvka's algorithm and edge filtering. It also discusses Karger's algorithm for approximating the global minimum cut in near-linear time using edge contractions. Finally, it presents an approach for 3-approximate distance oracles that preprocesses a graph to build a data structure for answering approximate shortest path queries in constant time using landmark vertices and storing local and global distance information.