MemorySanitizer is a tool designed to detect uninitialized memory reads in C and C++ programs. It helps developers identify and fix bugs that can lead to unpredictable behavior or crashes by ensuring that all memory is properly initialized before use. This is particularly useful in large codebases where tracking memory usage can be challenging. The tool works by instrumenting the code during compilation, adding checks that monitor memory access. When a program runs, MemorySanitizer reports any instances where uninitialized memory is read, allowing developers to address these issues early in the development process and improve software reliability.