We will discuss aspects related to generalized global symmetries in 4d supersymmetric theories. Specifically, the focus will be on 1-form symmetries, global form of flavor symmetries, and 2-group structures describing mixings between 1-form and flavor symmetries. We will also discuss confinement in terms of spontaneous breaking of 1-form symmetries. The discussion will include both Lagrangian theories and non-Lagrangian theories. We will get a handle on these symmetries by constructing the 4d theories by compactifying 6d N=(2,0) theories on punctured Riemann surfaces.