This document discusses the application of graph theory in modeling networks and parallel processing. It was written by K. Aurobindo Nayak, a CSE student with registration number 200101120022 who is studying at the Paralakhemundi campus. Some other applications of graphs mentioned include social networks, communication networks, software design, transportation networks, and biological networks. One well-studied collaboration graph is the Hollywood graph which connects movie actors who have appeared together in a film.