Memory allocation is the process by which a computer program requests and receives a specific amount of memory from the system's RAM (Random Access Memory). This allows the program to store and manage data while it is running. The operating system keeps track of which parts of memory are in use and which are free, ensuring that programs do not interfere with each other. When a program no longer needs the allocated memory, it can release it back to the system, a process known as deallocation. Proper memory allocation and deallocation are crucial for efficient program performance and to prevent issues like memory leaks, where unused memory remains allocated, potentially slowing down the system.