What is C-level (C-suite)?

What is C-level (C-suite)? 
TechTarget - CIO; by Rahul Awati and Mary K. Pratt; 8/27/24
... In recent years, positions like chief diversity officer (CDO), chief compliance officer (CCO), chief risk officer (CRO) and chief information security officer (CISO) have also emerged as part of the C-suite. Officers who hold C-level positions are typically considered the most powerful, influential members of an organization; consequently, they set the company's strategy, make high-stakes decisions, and ensure that daily operations align with fulfilling the company's strategic goals. ... Depending on the company type, size, country of operation and industry, the C-Suite might include some or all the following positions: [Explore this article for long-standing roles and new, emerging C-suite roles: CEO, COO, CFO, CMO, CIO, CTO, CHRO, CCO, CSO, CISO, CDO, CAO, CXO, CGO, CITA, CKI, CLO, CMIO, CPO, CPIO, CPO, CRO, CSS, CSO, CTO.]