The graphics cache saves the graphics contained in a document in your computer's main memory. This means that the attributes of a graphic stored in the cache do not have to be re-calculated if you return to the page containing the graphic after scrolling through a document.
图形缓存会将文档中的图形保存到计算机的主内存中。这样，当滚动到文档中含有图形的页面时，就无需再重新计算缓冲区中存储的图形属性。