In this paper, we discern different types of possible relations. We focus on the distinction between internal and external relations and their various possible sub-types. In the first section, we present what is nowadays more or less the standard distinction between internal and external relations. In the second section, we make two contributions to the literature of internal relations: a new taxonomy of internal relations and a novel distinction between formal and material ontological relations. In the third section, we discuss three distinctions among external relations, in particular the distinction between relata-specific and relata-unspecific relations. We argue that relata-specific external relations are a promising but incomplete solution to the vexed problem of Bradley’s relation regress.