Containers are used to define and contain the various sections of your page in the building tool
You can then add other blocks or more containers inside the container

To add content or another container below the current one click the + beside the container name block .

In the html code of your page they create

<div class= "xt_container" data-xtcontainer="container name">...... </div>
The data-xtcontainer="container name" is what tells the building tool to treat the block as a container

You can set the name of the container
(This shows in the building tool)

The css class "xt_container" is assigned to the container by default
You can add a second class to add more styles to the container
these must be defined in your global_stylesheet.css file
or with the page css editor from the building tool

There is also a alignment parameter to hold the basic "text-align" for the container

NOTE

If you delete a container
ALL the blocks it contains are also deleted

The container names
header
navigation
gallery
are reserved

and will create containers with the class
xt_header
xt_navigaton
xt_gallery
with special add navigation item or add gallery item blocks

Mobile users have the option in panel/settings/look and feel
to collapse the content of containers in the building tool to save space
just the blocks in the container will be listed when you open it