Proposal: Define basic terms: "entity", "repository", "identifier", etc.

spec/src/main/asciidoc/repository.asciidoc

@@ -34,11 +34,26 @@ In summary, the Repository pattern in Jakarta Data offers a structured and domai
 
 === Repositories on Jakarta Data
 
-A repository abstraction aims to significantly reduce the boilerplate code required to implement data access layers for various persistence stores.
+Within the context of Jakarta Data, a repository plays a pivotal role in simplifying data access layers for various persistence stores. It is a Java interface that acts as a gateway for accessing persistent data of one or more entity types. Repositories offer a streamlined approach to working with data by exposing operations for querying, retrieving, and modifying entity class instances that represent persistent instances of the entities they are associated with.
 
-In Jakarta Data, a repository is an interface that is annotated with the `@Repository` annotation.
+Several vital characteristics define repositories:
 
-The Jakarta Data specification defines several built-in interfaces from which repositories can inherit as a convenient way to include a variety of pre-defined methods for operations that are commonly used and to declare the entity type to use for methods from which the entity type cannot otherwise be inferred.
+- **Reduced Boilerplate Code:** One of the primary goals of a repository abstraction is to significantly reduce the boilerplate code required to implement data access layers for diverse persistence stores. This reduction in repetitive code enhances code maintainability and developer productivity.
+
+- **Jakarta Data Annotations:** In Jakarta Data, repositories are defined as interfaces and are annotated with the `@Repository` annotation. This annotation serves as a marker to indicate that the interface represents a repository.
+
+- **Built-In Interfaces:** The Jakarta Data specification provides a set of built-in interfaces from which repositories can inherit. These built-in interfaces offer a convenient way to include a variety of pre-defined methods for common operations. They also declare the entity type to use for methods where the entity type cannot otherwise be inferred.
+
+
+- **Data Retrieval and Modification:** Repositories facilitate data retrieval and modification operations. This includes querying for persistent instances in the data store, creating new persistent instances in the data store, removing existing persistent instances, and modifying the state of persistent instances. Conventionally, these operations are named insert, delete, and update for modifying operations and find, count, and exists for retrieval operations.
+
+- **Subset of Data:** Repositories may expose only a subset of the full data set available in the data store, providing a focused and controlled access point to the data.
+
+- **Entity Associations:** Entities within a repository may have associations between them, especially in the case of relational data access. However, this specification does not define the semantics of associations between entities belonging to different repositories.
+
+- **Stateless Repositories:** Repositories are typically designed to be stateless. However, it's important to note that this specification does not address the definition of repositories backed by Jakarta Persistence-style stateful persistence contexts.
+
+Repositories in Jakarta Data serve as efficient gateways for managing and interacting with persistent data, offering a simplified and consistent approach to data access and modification within Java applications.
 
 The parent interface at the root of the hierarchy of built-in interfaces is `DataRepository`. All of the built-in interfaces are extensible. A repository might extend one or more of the built-in interfaces or none of them. Method signatures that are copied from the built-in interfaces to a repository must have the same behavior as defined on the built-in interface.
 
@@ -87,17 +102,28 @@ public interface Garage extends CrudRepository<Car, String> {
 }
 ----
 
+Jakarta Data empowers developers to take control of their data access and management by providing the flexibility to define two essential components:
+
+1. **Entity Classes and Mappings:** Developers can define a set of entity classes and mappings tailored to a specific data store. These entities represent the data structure and schema, offering a powerful means to interact with the underlying data.
+
+2. **Repository Interfaces:** Jakarta Data encourages the creation of one or more repository interfaces, following predefined rules that include the guidelines set forth by this specification. These interfaces are the gateways to accessing and manipulating the data, offering a structured and efficient way to perform data operations.
+
+Subsequently, an implementation of Jakarta Data, specifically tailored to the chosen data store, assumes the responsibility of implementing each repository interface. This symbiotic relationship between developers and Jakarta Data ensures that data access and manipulation remain consistent, efficient, and aligned with best practices.
+
+Jakarta Data empowers developers to shape their data access strategies by defining entity classes and repositories, with implementations seamlessly adapting to the chosen data store. This flexibility and Jakarta Data's persistence-agnostic approach promote robust data management within Java applications.
 === Entity Classes
 
-Entity classes are simple Java objects with fields or accessor methods designating each entity property.
+In Jakarta Data, an entity refers to a fundamental data representation and management building block. It can be conceptually understood in several aspects:
+
+1. *Entity Classes*: Entity classes are simple Java objects equipped with fields or accessor methods that designate each property of the entity. Depending on your data storage needs, you may use annotations from the Jakarta Persistence specification, such as `jakarta.persistence.Entity`, `jakarta.persistence.Id`, and `jakarta.persistence.Column`, to define and customize entities for relational databases. Alternatively, for NoSQL databases, you can use annotations from the Jakarta NoSQL specification, including `jakarta.nosql.Entity`, `jakarta.nosql.Id`, and `jakarta.nosql.Column`.
 
-You may use `jakarta.persistence.Entity` and the corresponding entity-related annotations of the Jakarta Persistence specification in the same package (such as `jakarta.persistence.Id` and `jakarta.persistence.Column`) to define and customize entities for relational databases.
+2. *Data Schema*: Abstractly, an entity or entity type serves as a schema for data. It defines the structure and properties of the data it represents. This schema can be as simple as a set of typed fields, similar to the relational model, or more structured, as found in document data stores. The schema can be explicitly defined, as in the case of SQL Data Definition Language (DDL) declarations for relational tables, or it can be implicit, common in key/value stores.
 
-You may use `jakarta.nosql.Entity` and the corresponding entity-related annotations of the Jakarta NoSQL specification in the same package (such as `jakarta.nosql.Id` and `jakarta.nosql.Column`) to define and customize entities for NoSQL databases.
+3. *Persistence and Representation*: Entities are associated with persistent data, meaning the data outlives any specific Java process utilizing it. Each persistent instantiation of the schema is distinguishable by a unique identifier. For example, a row of a relational database table is identifiable by the value of its primary key. In Java, these entities are represented as classes, referred to as entity classes. It's important to note that multiple instances of the entity class within a Java program can represent a single persistent instance of the schema.
 
-Applications are recommended not to mix Entity annotations from different models for the sake of clarity and to allow for the Entity annotation to identify which provider is desired in cases where multiple types of Jakarta Data providers are available.
+4. *Provider Differentiation*: To maintain clarity and specify the desired provider when using Jakarta Data, it's recommended that applications do not mix Entity annotations from different models. This practice allows the Entity annotation to indicate the desired provider, especially in cases where multiple types of Jakarta Data providers are available. A Jakarta Data provider must provide implementation of repositories for Entity types having the Entity annotations that it supports, ignoring Entity types only having identifiable Entity annotations that the Jakarta Data provider does not support. The latter are to be handled by other Jakarta Data providers that do support the other types of Entity annotations.
 
-Repository implementations will search for the Entity annotation(s) they support and ignore other annotations.
+An entity within Jakarta Data encompasses the Java class representing the data and the schema, persistence characteristics, and provider-specific annotations, all working together to simplify data access and management within Java applications.
 
 === Query Methods