"Display in" of an article

I can't understand the use of this feature in articles.
There is a dropdown menu that says: "Main column, right. left, footer"

How can i use this?
I am asking becouse i am afraid if i am not doing something the proper way.


What was my problem:
Make an 'editable area' for the client with text editor at the right column.
The client should not go through modules(he will no have access there) to edit the text but he should see the article with all the others in the 'tree'.

Solution:
Make a new module -Costum HTML and put inside {{insert_article::10}} where 10 the id of the article.


thanks

When you create a page layout, the section "Included Modules" allows you to choose any modules you wish to add to the page and where you want them (header, main, right, etc.). One of these module options is "Articles".

For example you can add article modules to the main column and right column of your page layout. Then when you create an article, the "Display In" allows you to choose which you want the article to appear (of course you can also hide this in user group permissions if you don't want clients to have this ability).

The key is to make sure the article modules are added appropriately to the page layout, and that the page layout is actually used on the page you are adding articles to.

wowwww. amazing!!!
It was what i was looking for.

So, NO new layout need to be created for different presantation in Articles.
thank you so much