!13948 [翻译完成】#I66S8H

Merge pull request !13948 from Annie_wang/PR12680

en/application-dev/database/database-relational-overview.md

 # RDB Overview
 
-The relational database (RDB) manages data based on relational models. With the underlying SQLite database, the RDB provides a complete mechanism for managing local databases. To satisfy different needs in complicated scenarios, the RDB offers a series of methods for performing operations such as adding, deleting, modifying, and querying data, and supports direct execution of SQL statements.
+A relational database (RDB) store manages data based on relational models. With the underlying SQLite database, the RDB store provides a complete mechanism for managing data as in a local database. To satisfy different needs in complicated scenarios, the RDB store offers APIs for performing operations, such as adding, deleting, modifying, and querying data, and supports direct execution of SQL statements. After an application is uninstalled, the related RDB store will be automatically deleted.
 
 You do not need to care about the implementation of the database locking mechanism.
 
-## Basic concepts
+## Basic Concepts
 
-- **RDB**
+- **RDB store**
 
-  A type of database created on the basis of relational models. The RDB stores data in rows and columns. A RDB is also called RDB store.
+  A type of database created on the basis of relational models. A RDB store holds data in rows and columns.
 
 - **Predicate**
 
-  A representation of the property or feature of a data entity, or the relationship between data entities. It is mainly used to define operation conditions.
+  A representation of the property or feature of a data entity, or the relationship between data entities. Predicates are used to define operation conditions.
 
 - **Result set**
 
@@ -24,9 +24,9 @@ You do not need to care about the implementation of the database locking mechani
 
 ## Working Principles
 
-The RDB provides common operation APIs for external systems. It uses the SQLite as the underlying persistent storage engine, which supports all SQLite database features.
+The RDB store provides common operation APIs for external systems. It uses the SQLite as the underlying persistent storage engine, which supports all SQLite database features.
 
-**Figure 1** How RDB works
+**Figure 1** Working mechanism
 
 ![how-rdb-works](figures/how-rdb-works.png)
 
@@ -38,6 +38,6 @@ The RDB provides common operation APIs for external systems. It uses the SQLite
 
 ## Constraints
 
-- A maximum of four connection pools can be connected to an RDB to manage read and write operations.
+- An RDB store can be connected to a maximum of four connection pools to manage read and write operations.
 
-- To ensure data accuracy, the RDB supports only one write operation at a time.
+- To ensure data accuracy, the RDB store supports only one write operation at a time.