Page size refers to the amount of data that a single page in a computer's memory can hold. It is a crucial aspect of computer architecture, as it affects how efficiently data is stored and accessed. Common page sizes include 4 KB, 8 KB, and 16 KB, with larger sizes potentially reducing the number of pages needed but increasing wasted space if data does not fill the page. In operating systems, page size impacts virtual memory management. A smaller page size can lead to less wasted space but may increase the overhead of managing more pages. Conversely, a larger page size can improve performance by reducing the number of page table entries but may lead to inefficient memory use.