refer page, refer link, automatic

how do you code/implement an automatic link to a different  page from the 
one you land on? is it html? java script?
i can't find any at the moment to view the source. usually there is some 
content that says the site/page has moved and click a link to go there, or 
you will automagically be linked/sent  there in some few seconds if you 
don't do anything.