Final answer:
Compaction is a technique used to overcome external fragmentation in operating systems by rearranging memory to allocate contiguous blocks of memory for processes. It improves memory utilization and system performance.
Step-by-step explanation:
Compaction refers to a technique used to overcome external fragmentation in operating systems. It involves rearranging the memory to allocate contiguous blocks of memory for processes, reducing the amount of wasted space caused by fragmentation. This is commonly done through defragmentation algorithms, such as the buddy system or the segmentation and paging technique. Compaction helps improve memory utilization and system performance.