Groups are associated with a message. A group is a collection of all your blocks. Grouping allows you to link together Blocks in the system to show that they are included in a single email and should therefore count as being opened only once for the entire email (for billing purposes). It is therefore very important to link each block to a group. Otherwise, they will not appear in the email.
This has no effect on the scenario or how the Block functions. You can link up to 10 blocks to a single group.
When you are on the Groups tab in the application’s left menu, you can create a new group by clicking the “+” button in the top right corner.