Safari allows you to bookmark a web page or website and add it to a list so you do not have to type the web address in time after time. This can be useful for children to avoid mistyping a web address and ending up on a different site to the one they were trying to get to.
Safari on OS X
Different versions of OS X have slightly different ways to add a bookmark. Instructions on how to add a bookmark can be found here.
Safari on iOS
Location of Bookmarks in iOS