css - what is the difference between target value blank,self, parent,top in HTML? -

what difference between target value blank,self, parent,top,framename in tag target attribute? know blank open link in new tab self link open in current tab can't understand parent , top

from specification:

_blank

the user agent should load designated document in new, unnamed window.

_self

the user agent should load document in same frame element refers target.

_parent

the user agent should load document immediate frameset parent of current frame. value equivalent _self if current frame has no parent.

_top

the user agent should load document full, original window (thus canceling other frames). value equivalent _self if current frame has no parent.

http://www.w3.org/tr/html4/types.html#type-frame-target