The Container block can be used to add a CSS class around a group of consecutive blocks. This is done by adding a Container OPEN block and positioning it at the beginning of the group of blocks. Then create another Container CLOSE block and position it at the end of the group of blocks.
When you create the Container OPEN block, you will be asked to provide a CSS class name for the Container (i.e. for group of blocks). If you enter "group_1" then the CSS class name will be "b4u_container_group_1".
You will also be able to optionally specify a background image for the Container (i.e. for the group of blocks).
You can create multiple groups of blocks on a page by using multiple pairs of Container blocks. You must always have matched pairs of Container blocks (Open & Close) within a given region of your page, or if you are editing a page Template, then the Container blocks must be in pairs within each Template region (Regions: Top, Left, Right, Bottom).
Container groups cannot overlap each other nor be nested within each other.
If you have a Container block in a region that is out of sequence (e.g a CLOSE without an OPEN before it, or two OPENs in a row, etc.), then that out-of-sequence block plus all of the remaining blocks in the current region will have a warning background displayed to alert you to the issue.