The Group block is a block that groups other blocks together inside one container. Think of it as a “parent” block that can hold multiple “child” blocks within it.
Inserting a Group Block
In order to add a Group block, click on the block inserter icon (the plus sign) to open the block library and select the Group block:
After inserting a Group block, a block inserter icon will be displayed to allow you to add new blocks inside that Group block
After adding blocks inside a Group block, the Group block itself no longer shows. If you need to select the Group block again to access its settings, you can use the block navigation in the floating toolbar.