Which cloud computing tool is used to discover internal use of cloud services using various mechanisms such as network monitoring?

The cloud access security broker (CASB) is the correct answer because it serves as a critical middleware solution that provides visibility and control over the usage of cloud services within an organization. CASBs typically implement various mechanisms, including network traffic monitoring, to discover and manage internal cloud service usage effectively. This allows organizations to ensure compliance with security policies and identify any unauthorized or risky cloud applications being used by employees.

CASBs facilitate the monitoring of data traffic going to and from cloud applications, allowing entities to gain insights into which cloud services are being used, thereby identifying potential security risks associated with shadow IT—departments or employees using cloud services without IT's approval or oversight.

Data loss prevention (DLP) mainly focuses on preventing unauthorized data access and protection rather than discovering cloud service usage. Meanwhile, a content delivery network (CDN) is primarily concerned with optimizing the delivery of web content and enhancing performance rather than monitoring or securing cloud services. Lastly, a web application firewall (WAF) protects web applications from attacks but does not provide insights into the usage of cloud services or monitoring mechanisms within an organization.