Truth depends in some sense on reality. But it is a rather delicate matter to spell this intuition out in a plausible and precise way. According to the theory of truth-making this intuition implies that either every truth or at least every truth of a certain class of truths has a so-called truth-maker, an entity whose existence accounts for truth. This book aims to provide several ways of assessing the correctness of this controversial claim. This book presents a detailed introduction to the theory of truth-making, which outlines truth-maker relations, the ontological category of truth-making entities, and the scope of a truth-maker theory. The essays brought together here represent the most important articles on truth-making in the last three decades as well as new essays by leading researchers in the field of the theory of truth and of truth-making.