C2 has multiple names depending on the context. It can refer to several things:
C2 in Anatomy
In anatomy, C2 refers to the axis, the second cervical vertebra in the spine. This bone is located directly below the atlas (C1) and plays a crucial role in head rotation. The axis allows the head to pivot and rotate from side to side, as described in the Cleveland Clinic article on the cervical spine. "Your second vertebra (C2), also called the axis, allows the atlas to pivot against it for the side-to-side “no” rotation of your head." The articulation between C1 and C2 is stabilized by strong ligaments, as noted in the Spine-health article. "This joint is secured by a thick, strong ligament called the transverse ligament."
C2 in Cybersecurity
In cybersecurity, C2, or C&C, stands for Command and Control Infrastructure. This is a critical component of a cyberattack, used by attackers to communicate with compromised systems. Varonis explains that C2 "is the set of tools and techniques that attackers use to maintain communication with compromised systems." (https://www.varonis.com/blog/what-is-c2) Palo Alto Networks further clarifies this definition, stating it's a technique used by threat actors to communicate with compromised devices over a network. (https://www.paloaltonetworks.com/cyberpedia/command-and-control-explained)
C2 in Other Contexts
Beyond anatomy and cybersecurity, "C2" might also refer to:
- C2 gene: This gene provides instructions for making a complement component protein involved in the immune response, as detailed in MedlinePlus Genetics. (https://medlineplus.gov/genetics/gene/c2/)
- C2 Proficiency: This is a high-level English language qualification from Cambridge Assessment English. (https://www.cambridgeenglish.org/exams-and-tests/proficiency/)
- Synology C2 Object Storage: This is a cloud storage service offered by Synology. (https://kb.synology.com/C2/tutorial/C2_Object_Storage_Introduction)
- Fna C2 bacteria: A type of bacteria linked to colorectal cancer, according to the National Cancer Institute. (https://www.cancer.gov/news-events/cancer-currents-blog/2024/colorectal-cancer-fna-c2-bacteria)
The meaning of C2 depends entirely on the context.
