Vaccinology is the study of vaccines, their development, and their use. Classical vaccinology, practiced for centuries, relies on identifying and isolating a pathogen's protective antigens. Classical vaccinology has successfully developed vaccines against many diseases, including smallpox, measles, mumps, and diphtheria. However, it can be a time-consuming and labor-intensive process. Immunoinformatics offers a new approach to vaccine development that can address some of the limitations of classical vaccinology. This interdisciplinary field combines biology and computer science to explore the immune system's interactions. In the last decade, technological advances, such as big data, machine learning, and artificial intelligence, are enabling new advances in Immunoinformatics, potentially revolutionizing vaccine development. This chapter aims to provide a comprehensive overview of Immunoinformatics, its techniques, and its applications, exploring its foundations, advances, and future perspectives.