M-theory is a theoretical framework in physics that aims to unify the five different versions of string theory. It suggests that the fundamental building blocks of the universe are not just one-dimensional strings, but also higher-dimensional objects called branes. This theory operates in eleven dimensions, which include the familiar three dimensions of space and one of time, plus additional dimensions that are compactified. One of the key motivations for M-theory is to provide a comprehensive understanding of quantum gravity and the fundamental forces of nature. It seeks to explain how particles and forces interact at the most basic level, potentially offering insights into phenomena like black holes and the early universe.