Attaching a link with each post very much useful for a Google or for any search Engine, If you have similar kind of post or contents in two articles then search engines may not able to identify which is exact link of this post, it might be display other link in search result along with the Title.So to avoid this thing, good to have to have associated link for each post,whenever you make any post, must tag link with title.
How to Make Setting to Enable the Link Field :-
After Login in Blogger , Go in Setting > Formatting , see the Label Show Link fields.Now make it Yes, You will able to see the Link field for each post along with the Title Field.
How to Attach link with The Title :-
First post the article which you want to publish, as you post the article, the link will be created.Now go in Posting > Edit Post. You will get the recent post article, make right click on view link, copy your link address through the option and click on edit post provide the link in Link Field and re-publish the post, now your link got successfully saved with the Title.