Final answer:
A dynamic allocation policy allows the flexibility to change the number of page frames allocated to a process over its lifetime, which can lead to more efficient memory usage.
Step-by-step explanation:
A dynamic allocation policy allows the number of page frames allocated to a process to be varied over the lifetime of the process. In operating systems that use paging for memory management, when a program is running, it is divided into blocks of memory called pages.
The operating system then allocates a certain number of page frames in the physical memory where these pages can reside. A dynamic allocation policy adjusts the number of page frames allocated to each process, depending on various factors such as process size, working set, and multitasking demands.
For example, under variable allocation, a system might increase the number of page frames for a process if that process is currently active and needing more memory, hence improving its performance. Conversely, if the process is inactive or requires less memory, the system could decrease its allocation.
This flexibility can lead to more efficient use of memory and enhanced system performance, but it also requires careful management to avoid issues like thrashing.