The physical interpretation of the mathematical descriptions of general relativity gives rise to a range of exciting consequences in cosmology. An understanding of general relativity is therefore a prerequisite for students wishing to pursue further courses or research projects in cosmology and its various subfields from black holes to gravitational waves. Written for advanced students and including numerous exercise problems, this book is a rigorous resource for students in theoretical physics and mathematics requiring an introduction to the implications and interpretation of general relativity in areas of modern cosmological research. Readers of this text will be well prepared to follow the theoretical developments in the field and undertake research projects as part of an MSc or PhD programme.