What is the main characteristic of a memory leak?

The main characteristic of a memory leak is a gradual loss of available memory over time. This occurs when a program allocates memory for data but fails to release it back to the system after it is no longer needed. As the program continues to use memory without freeing it, the total amount of available memory decreases, leading to less memory being available for other processes. Eventually, this can lead to performance degradation or even application crashes, but the defining aspect of a memory leak is this slow, steady consumption of memory resources.

In contrast, the other options do not capture the essence of a memory leak. Sudden data loss is typically associated with abrupt crashes or failures, not with the gradual depletion nature of a memory leak. Increased processing speed does not relate to memory management and is not a characteristic of memory leaks—rather, leaks can lead to slowed performance due to strain on available resources. Frequent application crashes might occur as a result of a severe memory leak, but this is not a defining characteristic; instead, it is an outcome of a memory leak that has persisted long enough to exhaust system resources.