Explanation
Database tables are data structures that store information in two dimensions, using rows and columns. Each row represents a record or an entity, and each column represents an attribute or a field. Database tables may have key fields, which are columns that uniquely identify each row or a subset of rows. Key fields can be used to enforce data integrity, perform efficient searches, and establish relationships to other tables. Database tables can have relationships to other tables, which are associations or links between the key fields of two or more tables. Relationships can be used to model the logical connections between different entities, join data from multiple tables, and enforce referential integrity12.
References: 1: Table (database) - Wikipedia 2: Database design basics - Microsoft Support

Explanation
In RESTful Application Programming, a business object contains two main parts: a CDS view and a behavior definition1.
A). CDS view: A CDS view is a data definition that defines the structure and the data source of a business object. A CDS view can consist of one or more entities that are linked by associations or compositions. An entity is a CDS view element that represents a node or a projection of a business object. An entity can have various annotations that define the metadata and the semantics of the business object2.
B). Behavior definition: A behavior definition is a source code artifact that defines the behavior and the validation rules of a business object. A behavior definition can specify the standard CRUD (create, read, update, delete) operations, the draft handling, the authorization checks, and the side effects for a business object. A behavior definition can also define custom actions, validations, and determinations that implement the business logic of a business object3.
The following are not parts of a business object in RESTful Application Programming, because:
C). Authentication rules: Authentication rules are not part of a business object, but part of a service binding. A service binding is a configuration artifact that defines how a business object is exposed as an OData service. A service binding can specify the authentication method, the authorization scope, the protocol version, and the service options for the OData service4.
D). Process definition: Process definition is not part of a business object, but part of a workflow. A workflow is a business process that orchestrates the tasks and the events of a business object. A workflow can be defined using the Workflow Editor in the SAP Business Application Studio or the SAP Web IDE. A workflow can use the business object's APIs to trigger or consume events, execute actions, or read or update data5.
References: 1: Business Object | SAP Help Portal 2: CDS View Entities | SAP Help Portal 3: Behavior Definition | SAP Help Portal 4: Service Binding | SAP Help Portal 5: Workflow | SAP Help Portal

Explanation
The function module ZF1 is in a software component with the language version set to "ABAP Cloud". This means that it follows the ABAP Cloud Development Model, which requires the usage of public SAP APIs and extension points to access SAP functionality and data. These APIs and extension points are released by SAP and documented in the SAP API Business Hub1. Customer-created function modules are not part of the public SAP APIs and are not released for cloud development. Therefore, calling a function module directly from a class with the language version set to "Standard ABAP" is not allowed and will result in a syntax error.
However, there is a possible way to call a function module indirectly from a class with the language version set to "Standard ABAP":
Create a wrapper class or interface for the function module and release it for cloud development. A wrapper is a class or interface that encapsulates the function module and exposes its functionality through public methods or attributes. The wrapper must be created in a software component with the language version set to "ABAP Cloud" and must be marked as released for cloud development using the annotation @EndUserText.label. The wrapper can then be called from a class with the language version set to "Standard ABAP" using the public methods or attributes2.
For example, the following code snippet shows how to create a wrapper class for the function module ZF1 and call it from the class zcl_demo_class:
@EndUserText.label: 'Wrapper for ZF1' CLASS zcl_wrapper_zf1 DEFINITION PUBLIC FINAL CREATE PUBLIC. PUBLIC SECTION. CLASS-METHODS: call_zf1 IMPORTING iv_a TYPE i iv_b TYPE i EXPORTING ev_result TYPE i. ENDCLASS.
CLASS zcl_wrapper_zf1 IMPLEMENTATION. METHOD call_zf1. CALL FUNCTION 'ZF1' EXPORTING a = iv_a b = iv_b IMPORTING result = ev_result. ENDMETHOD. ENDCLASS.
CLASS zcl_demo_class DEFINITION. METHODS: m1. ENDCLASS.
CLASS zcl_demo_class IMPLEMENTATION. METHOD m1. DATA(lv_result) =
zcl_wrapper_zf1=>call_zf1( iv_a = 2 iv_b = 3 ). WRITE: / lv_result. ENDMETHOD. ENDCLASS.
The output of this code is:
5
References: 1: SAP API Business Hub 2: Creating an ABAP Cloud Project | SAP Help Portal

Explanation
When accessing the subclass instance through go_super, you can do both of the following:
Access the inherited private components: A subclass inherits all the private attributes and methods of its superclass, unless they are explicitly overridden by the subclass. Therefore, you can access the inherited private componentsof the superclass through go_super, as long as they are not hidden by other attributes or methods in the subclass12.
Access the inherited public components: A subclass inherits all the public attributes and methods of its superclass, unless they are explicitly overridden by the subclass. Therefore, you can access the inherited public components of the superclass through go_super, as long as they are not hidden by other attributes or methods in the subclass12.
You cannot do any of the following:
Call a subclass specific public method: A subclass does not have any public methods that are not inherited from its superclass. Therefore, you cannot call a subclass specific public method through go_super12.
Call inherited public redefined methods: A subclass does not have any public methods that are redefined from its superclass. Therefore, you cannot call inherited public redefined methods through go_super12.
References: 1: Object Oriented - ABAP Development - Support Wiki 2: Inheritance and Instantiation - ABAP Keyword Documentation