Otavio, thanks for the answer.
So, I was reading the documentation and I thought about the explanation about layers.
The Communication Layer is defined as "A set of APIs that defines communication with NoSQL databases." and in the Mapping layer "These APIs help developers to integrate their Java application with the NoSQL database."
The first paragraph says that the project defines a set of API's and this information repeats in the explanation of the communication layer. There is a repetition about both layers communicate or integrate with nosql databases. Maybe if we change for:
"The project has two layers that define communication with NOSQL databases through API's. There are:
1 - Communication Layer: Contains four modules, one for each NoSQL database type: Key-Value, Column Family, Document and Graph.
Compared with traditional the RDBMS world, they are like the JDBC API.
2 - This layer is annotation-driven and uses technologies like CDI and Bean Validation, making it simple for developers to use.
In the traditional RDBMS world, this layer can be compared to the Java Persistence API or object-relational mapping frameworks such as Hibernate."
I think that this way doesn't need to repeat that both communicate or integrate with nosql databases and focus on differences about the layers.
I'm still reading the documentation, but had this feeling about this part above. If I have another suggestion, I will send it here and you can see if it changes or not.
Thanks for your attention.