internet single entity complex network networks connects millions computers devices around world has different layers physical layer cables routers servers transmit data logical protocols rules govern exchange application websites apps services online understand geometric shape need consider structured connected way graphs mathematical models represent using nodes points edges lines Graphs capture various properties size density degree distribution clustering centrality modularity Different model aspects example graph mapping locations connections backbone form core autonomous systems groups administrative domain web pages hyperlinks World Wide Web depending arranged Some regular shapes circles squares hexagons evenly distributed irregular stars trees jellyfishes clustered hierarchical fractal snowflakes ferns exhibit self-similarity scales answer what depends aspect looking dynamic diverse system multiple dimensions