This is an opening chapter of the book where the basic concepts and definitions are introduced, and they are further discussed in the following chapters. The common ground with the terms and targets is set. Difference between equality and equity is explained, concept of intersectionality is underlined, and the need for diversity and inclusion is described. Gender bias and stereotypes have negative effects on all people and communities. They relate to a culture that does not tolerate diversity. Gender equality and equity are not just “technical things”. They will not be solved by simply counting gender at different positions and ticking the boxes. It is a highly political issue that requires a substantial level of social consensus to move forward. This book reflects the need that the challenges which perioperative and critical care medicine share with the global society are recognized and to discuss the ways to address them. However, medical environment has some specific interests that are highlighted in recent years. Sex- and gender-informed medicine is a new paradigm of clinical practice and medical research that considers the association of sex and gender with each element of the disease process from risk to presentation, and to response to therapy. Many gaps in knowledge remain. This book contains a call to action for a culture of change and provision of better healthcare based on fairness, diversity, and inclusion.