Branes in String/M-Theory

This is the writeup of lectures delivered in Asian Pacific introductory school on superstring and the related topics in Beijing (2006) and the expanded version of these lectures in the 3rd summer school on strings, fields and holography in Nanjing (2023). It intends to give a historical as well as a pedagogical account of the development in finding the 1/2 BPS extended string solitons in the early stage of the so-called second string revolution before which those objects were thought to be unrelated to strings. Non-susy solutions which are related to brane/anti brane systems or non-BPS systems are also discussed.