1. With computers, page size refers to the size of a page, which is a block of stored memory. Page size affects the amount of memory needed and space used when running programs. Most operating systems allow for the determination of the page size when a program begins running, which allows it to calculate the most efficient use of memory while running that program.
2. With Web pages, page size (also called page weight) refers to the overall size of a particular Web page. A page size includes all of the files that are used ot create the web page: The HTML document, any included images, style sheets, scripts, and other media. For example, a Web page that has an HTML document that is 10K in size, a 20K image file, and a 5K style sheet file, would have a page size of 35K.
3. With print documents, page size typically refers to the size of the paper the document will be printed on, such as letter size (8.5 x 11 inches) or legal (8.5 x 14 inches).