The CTO is the Chief Technology Officer of an enterprise, sometimes known as chief technical officer or chief technologist.
CSO: Chief Security Officer
The acronym CSO can be used for either Chief Security Officer, this often refers to physical security but can also include cyber security.
The acronym can also stand for Chief Science Officer or Chief Scientific Officer.
CSIRT: Computer Security Incident Response Team
A CSIRT is a Computer Security Incident Response Team. It is often synonymous with CERT.
CREST: The Council for Registered Ethical Security Testers
CREST is The Council for Registered Ethical Security Testers, which is an UK organisation.
CISSP: Certified Information Systems Security Professional
A Certified Information Systems Security Professional is often referred to as CISSP. It is a certification administered by the International Information System Security Certification Consortium, which is also known as (ISC)².
CiSP: Cyber Security Information Sharing Partnership
The CiSP is the Cyber Security Information Sharing Partnership which is an NCSC scheme in the United Kingdom.
CISO: Chief Information Security Officer
Chief Information Security Officer is usually represented by the acronym CISO.
CISOs exist in a large number of organisations, typically larger enterprises, and they generally look after the cyber security and privacy aspects of an organisation.
CIP: Critical Infrastructure Protection
The acronym CIP is used for Critical Infrastructure Protection. It is typically for the safety and security (not just cyber) of Critical National Infrastructures (CNI).
In the United Kingdom, the physical safety and security of CNI is looked after by the CPNI. The cyber security aspects of CNI are looked after by NCSC in the UK.