If you navigate to Content > Items for the first time, you will notice that you will see an empty list, this is because you first have to mark items as ChannelEngine (CE) items before they can be synchronized with ChannelEngine. 

To do so, go to Items (the standard BC item list), open an item, and click on Create a new CE Item. This ChannelEngine Status is an interactive status field. It will show the actual life cycle status of an item, from being a non-CE item, to being an item which is published and actively synchronized with ChannelEngine. 

After clicking this status link for the first time, you will see a notification which can be used to open CE item you have just created. From now on you will also find this item under Content > Items, and you can start to work on the details that define how your items will look on the marketplaces.

Before an item is published to ChannelEngine, there is a final release switch. This is to make sure that you can work on the content of an item for as long as needed. Only once released the item will be pushed to ChannelEngine. 

In case an item is released it will be placed in the CE Integration Queue, where it will be picked up and processed by the synchronization mechanism. Once synchronized for the first time, you will see that the Synchronized field on the CE item is active. And from this point on the system will monitor all relevant changes and it will immediately synchronize the item when needed.