Some blocks placed on pages can have configurable options, and those options can be different for each page that the block is placed on. Configure properties for a block by clicking on the block within a page. (Note that not all blocks have options that can be edited.) The types of things that can be edited for each block vary widely.
Options set for a block on one page only apply to the block on that specific page. Two calendars placed on the same page can be configured differently!