This tutorial explores the diversity and characteristics of C-donor ligands. Particular emphasis is put on the conceptual design of the electronic properties for applications in coordination chemistry. More specifically, the implications of both σ and π effects are discussed. Cyclic (alkyl)(amino)carbenes as well as methanediides and carbones are brought in perspective to "conventional" N-heterocylic carbenes, mesoionic carbenes, and Fischer as well as Schrock carbene ligands.