The Purdue Reference Model, as adopted by ISA-99, is a model for Industrial Control System (ICS) network segmentation that defines six layers within these networks, the components found in the layers, and logical network boundary controls for securing these networks.
Defence In Depth
A defense-in-depth strategy refers to a cybersecurity approach that uses multiple layers of security for holistic protection. A layered defense helps security organizations reduce vulnerabilities, contain threats, and mitigate risk. In simple terms, with a defense-in-depth approach, if a bad actor breaches one layer of defense, they might be contained by the next layer of defense.
ISP - Internet Service Provider
An Internet service provider is an organization that provides services for accessing, using, or participating in the Internet.
SOC: Security Operations Centre
A Security Operations Centre (SOC) is a place or team where a network or system is monitored or defended.
They often employ a number of technologies, such as an IDS.
SaaS: Software as a Service
SaaS stands for Software as a Service.
Quite literally SaaS is a software product provided as a service. Quite often this means that it is some kind of web application managed by an organisation. This application may be served through a cloud service such as Amazon Web Services (AWS), Google Cloud or Microsoft Azure (other cloud services are available).
SIEM: Security Information and Event Management
SIEM stands for Security Information and Event Management. SIEM could be a product or service which manages information/data and the changes in that information/data (“events”).
A SIEM may be used by a SOC.
Security-by-Design
Security-by-design means ensuring that cyber-security is a key part of the system from the design and throughout the development and deployment of that system.
PenTesting / Penetration Testing
Penetration Testing, or Pen Testing for short, is the process of purposefully testing a system to see if it can be hacked. Pen testers are also often called ethical hackers.