\input zb-basic \input zb-ioport \iteman{io-port 06087771} \itemau{Criado, Regino; Romance, Miguel} \itemti{Structural vulnerability and robustness in complex networks: different approaches and relationships between them.} \itemso{Thai, My T. (ed.) et al., Handbook of optimization in complex networks. Communication and social networks. New York, NY: Springer (ISBN 978-1-4614-0856-7/hbk; 978-1-4614-0857-4/ebook). Springer Optimization and Its Applications 58, 3-36 (2012).} \itemab Summary: The concept of vulnerability in the context of complex networks quantifies the capacity of a network to maintain its functional performance under random damages, malicious attacks, or malfunctions of any kind. Different types of networks and different applications suggest different approaches to the concept of networks structural vulnerability depending on the aspect we focus upon. In this introductory chapter, we discuss some different approaches and relationships amongst them. \itemrv{~} \itemcc{} \itemut{} \itemli{doi:10.1007/978-1-4614-0857-4\_1} \end