A "Null Pointer" is a special type of pointer in programming that does not point to any valid memory location. It is often used to indicate that a variable has not been initialized or that it is intentionally set to point to nothing. When a program tries to access or manipulate data through a null pointer, it can lead to errors or crashes, commonly known as a Null Pointer Exception. In many programming languages, such as C, C++, and Java, null pointers are a common source of bugs. Developers must check for null pointers before using them to ensure that the program runs smoothly. Proper handling of null pointers is essential for writing robust and error-free code.