What is a pointer in programming?

A pointer is indeed defined as a variable that stores the memory address of another variable. This concept is fundamental in programming, particularly in languages like C and C++, where memory management and direct memory access are pivotal.

Pointers allow for efficient data manipulation and can lead to performance enhancements because they enable developers to work with memory addresses directly. This capability allows for dynamic memory allocation, enabling programs to handle variable-sized data structures, such as linked lists and trees, effectively. By using pointers, a programmer can efficiently manage resources, pass large data structures to functions without copying entire objects, and create complex data architectures.

In contrast, the other options represent different concepts. A type of data structure refers to organized formats for storing and organizing data, such as arrays or lists, but does not encapsulate the essence of what a pointer does. A high-level abstraction of data manipulation relates to programming concepts that make operations simpler and more user-friendly but do not pertain to pointer functionality. Lastly, a debugging tool may assist in identifying and resolving issues in code but does not define the role of pointers in managing memory addresses or variable references.