Offensive Security is the concept of building security capabilities through attacking the assets to be protected. This approach makes it possible to identify weaknesses in the same way that a real malicious would do, with the difference that once a weakness is confirmed, the service would suggest the necessary recommendations to facilitate its resolution and ultimately improve resilient against real attacks.
Red Teaming is an example of Offensive Security Services, whose ultimate goal is to help organizations to protect their assets from real attackers.