The autophagy core machinery carries out to the fundamental reactions of autophagosome biogenesis across all forms of bulk and selective macroautophagy. In humans, the core complexes consist of the ULK1 complex (ULK1C), the class III phosphatidylinositol 3-kinase complex I (PI3KC3-C1), the ATG8 proteins and the ATG8ylation machinery, the PI3P-sensing WIPI proteins, the lipid transporter ATG2, and the lipid scramblase and initiation scaffold ATG9. These complexes form a web of interactions that can be initiated by clustering of the FIP200 subunit of ULK1C, but also by PI3KC3-C1 or WIPI proteins. Upon autophagy induction, these interactions are intensified by feed-forward signaling loops. These loops are amplified by WIPI-PI3P interactions and the conjugation of ATG8 proteins to the membrane by the ATG12-ATG5-ATG16L1 complex. This lecture will put the conserved features of the various types of bulk and selective autophagy into perspective on the basis of common structural and functional aspects of the core machinery.