In a baseline ServiceNow instance, the available domain types include Primary, TOP, and Customer. These domain types are part of the domain hierarchy that ServiceNow uses to organize data, processes, and administrative tasks within the platform.

* Primary: This is the main domain where the instance is initially set up. It's the starting point for the domain hierarchy and typically contains the core configurations and settings for the instance.

* TOP: The TOP domain is the highest level in the domain hierarchy, above all other domains. It is used for defining global processes and settings that can be inherited by lower-level domains.

* Customer: Customer domains are created to represent individual customers or tenants in a multi-tenancy environment. Each customer domain can have its own unique configurations, processes, and data that are separate from other domains.

The concept of MSP (Managed Service Provider) and Vendor domains are not standard domain types in a baseline instance but can be configured as part of a domain separation strategy to cater to specific business needs. The ServiceNow documentation provides detailed information on domain separation, including the types of domains and how they are used within the platform. Domain separation allows organizations to maintain data privacy and process customization across different business entities within a single instance of ServiceNow.

In ServiceNow, domain separation allows for the partitioning of data, processes, and administrative tasks into distinct domains within the same instance. When it comes to business rules, if a business rule exists in the parent domain and another non-overriding business rule exists in the child domain, both rules will be executed for the child domain1.

This behavior is part of the domain hierarchy logic, where the child domain inherits the properties and rules of its parent unless explicitly overridden. Since the business rule in the child domain is non-overriding, it does not cancel or replace the parent domain's rule. Instead, it adds to the logic that will be processed when the conditions for the business rule are met.

Therefore, when an action occurs that triggers the business rules, the system will first run the business rule from the parent domain followed by the business rule from the child domain. This ensures that the foundational logic set by the parent domain is always applied, while still allowing for additional, domain-specific customizations in the child domains2.

It's important to note that this behavior can be controlled and configured according to the needs of the organization, and understanding the implications of domain inheritance is crucial for proper domain separation management in ServiceNow3.

Before using domain separation for Service Catalog items, the first step an administrator must perform is to activate the Service Catalog - Domain Separation plugin (com.glideapp.servicecatalog.domain_separation). This plugin enables domain separation within the Service Catalog, allowing for the separation of data, processes, and administrative tasks into logical groupings called domains1. By activating this plugin, the admin ensures that the Service Catalog is prepared to handle the complexities of a domain-separated environment, which is essential for maintaining data integrity and proper access controls across different domains21.

In ServiceNow, when a new record is created on a standalone table, the domain of the new record is set to the user's current session domain by default. This means that the domain context in which the user is operating at the time of record creation determines the domain assignment for that record. This behavior ensures that the data is correctly categorized within the domain structure, adhering to the visibility and access controls that have been established.

The concept of domain separation in ServiceNow is integral to its multi-tenancy model, allowing for data, processes, and administrative tasks to be segregated across different domains within a single instance. This is particularly useful for managed service providers (MSPs) who need to maintain distinct operational environments for multiple customers or departments within the same ServiceNow instance.

For a new standalone table, unless explicitly defined otherwise, the system defaults to using the user's current session domain for new records. This is supported by ServiceNow's documentation on domain separation best practices and the management of data within domains12. It's important to note that while the default behavior is as described, administrators have the ability to configure domain rules and behaviors to suit specific organizational needs.

In ServiceNow's domain separation model, data accessibility is designed to maintain the integrity and segregation of data across different domains. Here's how data accessibility works between parent and child domains:

* The parent users can access all child data: Users in a parent domain have visibility into the data of their child domains. This is because the parent domain is considered to have a higher level of data access privilege, allowing it to oversee and manage the data within its child domains1.

* The parent users can access all child data, but cannot access domains contained in the child domain: While parent domain users can access data in their immediate child domains, they cannot access data in ''grandchild'' domains or any domains that are further nested within a child domain. This maintains a level of data isolation and ensures that users only have access to the data they are permitted to view and manage1.

The options stating that both parent and child users can access each other's data (A) and that child users can access all parent data are incorrect. The domain separation model is hierarchical, not reciprocal, meaning that child domains do not have inherent access to parent domain data, and access between domains is not automatically bidirectional1.

For detailed information on domain separation and data accessibility, ServiceNow provides extensive documentation and best practices, which can be referenced for a deeper understanding of these concepts12