Self - Open the linked web page in the same browser window
New - Open the linked web page in a brand new browser window
Parent - Open the linked web page in the "parent" browser window, applicable when you add a link that is embedded in an iFrame
Most of the time, users will want to leave link option at the default "Open in the same window" (self).
When you wish to launch the link in a new browser tab, the "Open in new window" option can be used.
The "Open in parent frame" link option is usually used when you plan to embed the current page into another page through an iFrame. For example, when page A is embedded within page B, page B becomes the "parent" frame of page A.
When a link on page A is tapped, it will open in its parent frame, which in our example, is page B.
The parent frame option is also often used when one wishes to embed a navigation menu into a web page. In this case, the navigation menu will be built in its own independent page, and will have all of its links set to open in the "parent" frame. This way, to use the menu, you will simply need to embed it to any new web page using an iFrame (with an HTML Snippet).