Karapınar, E.Agarwal, R.P.2025-05-132025-05-1320221938-1743https://doi.org/10.1007/978-3-031-14969-6_4https://hdl.handle.net/20.500.12416/9731In this chapter, we discuss some of the interesting generalizations and extensions of the notion of the metric. Roughly speaking, the notion of metric can be considered as an axiomatic form of the “distance”. For this reason, the metric and all generalizations and extensions of the metric can be called “distance function”. One of the well-known examples of the metric is due to Euclid which is known as Euclidean metric. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.eninfo:eu-repo/semantics/closedAccessBook Part10.1007/978-3-031-14969-6_42-s2.0-85143746381