A 2 or 3 tier architecture is not specific to Check Point.
From Wikipedia:
In software engineering, multitier architecture (often referred to as n-tier architecture) or multilayered architecture is a client–server architecture in which presentation, application processing, and data management functions are physically separated. The most widespread use of multitier architecture is the three-tier architecture.
Network security devices such as Check Point can be deployed to protect this sort of architecture.
That said, the Check Point general approach to information security is described in the Software Defined Protection framework, which partitions the security infrastructure into three interconnected layers:
An Enforcement Layer that is based on physical, virtual and host-based security enforcement points and that segments the network as well as executes the protection logic in high-demand environments.
A Control Layer that analyses different sources of threat information and generates protections and policies to be executed by the Enforcement Layer.
A Management Layer that orchestrates the infrastructure and brings the highest degree of agility to the entire architecture.
The Software-Defined Protection Enterprise Security Blueprint describes the architecture in more detail and provides several design patterns for enterprise networks.
