You can have an Asset with a corresponding Configuration Item record. For example, a personal computer typically falls into this situation.
You can have an Asset without a correlating Configuration Item record. In your first screenshot, the monitor falls into this example. There is no monitor record within the configuration management database (CMDB).
You can have a Configuration Item that does not have a relationship to an asset. An example of this can be logical services such as Application Services, Business Services, etc.
There is a really good deck in NowCreate called ITSM Asset Management - Process Workshop that may help you out.
This article also may help you out - Docs | Asset and CI management
When an asset has a corresponding configuration item, the asset record and the configuration item record are kept synchronized with two business rules.
- Update CI fields on change (on the Asset [alm_asset] table)
- Update Asset fields on change (on the Configuration Item [cmdb_ci] table)
