What Is the Difference Between Adding a Resource Tag and Creating a Tag Key?

When you add a resource tag and set only the tag key, the tag value is empty by default. The tag will be associated with a resource after it is added. You can add resource tags like this in batches.

If you create a key, a column with the key as the header will be added to the resource tag list, and the value is set to Not Tagged by default. To attach tags with the key created to resources, add values for the key in the rows that contain the target resources. If you do not add any values for the key, the key will not be associated with any resources.

The following picture shows a tag of a VPC with the key set to Owner and the value left empty. It also shows a created key, Usage.

Figure 1 Example