when we use the _parent target attribute in an anchor <a> tag,it opens the linked document in parent window. can anyone tell me that what is a parent frame?
This comes from the time when websites were developed using frameset, something which is not used anymore nowadays. You could divide your page in say 3 frames and when a link was clicked only the frame where you were in was reloaded, it was a way to reduce traffic between the browser and the server. Using the _parent allowed to open a link in the main browser window. To understand it better see the demo I set up for you in http://www.corobori.com/sos/frames/FramePage.html showing how it works.