Types of graphs and algorithms uses in social media networking

Algorithms are used here, Page Rank Algorithm, Random walk with Restart Algorithm, Shortest Path.
These are used to connect people via Internet or Social media with each other as far as possible.
These nodes in a social media are interdependent on each other via common interests, relations, mutual friends, knowledge, common dislikes, beliefs etc.
Graphs are used here are, we can say Bipartite graph, Trees, Weighted graphs
Graph Partition is also use in social media networking