The article provides an introduction to loop quantum gravity, a background-independent, non-perturbative approach to unifying general relativity and quantum physics. It emphasizes the quantum theory of geometry and is pedagogical in nature, aiming to serve as an accessible entry point into the field. The authors discuss the conceptual viewpoint, physical questions, and the progress made in addressing these issues. The article covers connection theories of gravity, quantization strategies, background-independent kinematics, quantum Riemannian geometry, quantum dynamics, applications to quantum cosmology and black hole entropy, and current directions. It also includes appendices on the inclusion of matter fields and a list of symbols. The review highlights the importance of understanding the fundamental microstructure of geometry and the challenges in addressing singularities, black holes, and the Planck scale physics. The article concludes with a summary and outlook on the field.The article provides an introduction to loop quantum gravity, a background-independent, non-perturbative approach to unifying general relativity and quantum physics. It emphasizes the quantum theory of geometry and is pedagogical in nature, aiming to serve as an accessible entry point into the field. The authors discuss the conceptual viewpoint, physical questions, and the progress made in addressing these issues. The article covers connection theories of gravity, quantization strategies, background-independent kinematics, quantum Riemannian geometry, quantum dynamics, applications to quantum cosmology and black hole entropy, and current directions. It also includes appendices on the inclusion of matter fields and a list of symbols. The review highlights the importance of understanding the fundamental microstructure of geometry and the challenges in addressing singularities, black holes, and the Planck scale physics. The article concludes with a summary and outlook on the field.