I didn't understand this first question

Answer 1

A target specifies where to open link
for example you can use _blank to open that link in a new tab of your browser. You can also use _top,_parent etc.😊

Answer 2

How the mark up language identify contents.
it identifies with the help of tags 😊😊

Answer 3

thanks I have already done

Answer 4

explain more about the attributes target please