In mathematics, topology is the study of the properties of space that are preserved under continuous deformations.
Network topology refers to the arrangement of the elements of a communication network, such as links and nodes. This most likely referencing how the Topologics are CyberseLink Monsters whose effects activated when linked.
"Topologic" monsters usually involve mass destruction of cards whenever a monster is Special Summoned to a Zone a Link Monster points to. In addition, they inflict heavy effect damage.