If you want to clear the cache of another page or folder after editing a page or folder, you usually have to do this manually. This is bad if plugins on another page changing contents of records, and the cached frontend doesn´t refresh that content.
The folder with id 1 got edited. Page 42 contains a frontend plugin which uses records of folder 1.
After editing something of folder 1, the cache of page 42 should be cleared automatically.
Open the page settings of your page/folder (folder 1 in our example) and add the following code into the Page TSconfig (Page > Edit > Resources).
# Clear cache of page 42 after any changes on this page/folder. TCEMAIN.clearCacheCmd = 42