The four cloud deployment models are
1. Public
2. Private
3. Hybrid
4. Community

Static application security testing(SAST) is generally considered a white-box test, where the application test performs an analysis of the application source code, byte code, and binaries without executing the application code. SAST is used to determine coding errors and omissions that are indicative of security vulnerabilities. SAST is often used as a test method while the tool is under development(early in the development lifecycle).
SAST can be used to find XSS errors, SQL injection, buffer overflows, unhandled error conditions, and potential backdoors.

According to "The NIST Definition of Cloud Computing," in IaaS, "the capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software, which can include OSs and applications. The consumer does not manage or control the underlying cloud infrastructure but has control over OSs, storage, and deployed applications; and possibly limited control of select networking components (e.g, host firewalls)."

A content delivery network(CDN) is a system of distributed servers(network) that deliver pages and other Web content to a user. based on the geographic locations of the user. the origin of the webpage and the content delivery server.

SIEM is a combination of Security Incident Management(SIM)and Security Event Management(SEM).
A SEM system centralizes the storage and interpretation of logs and allows near real-time analysis which enables security personnel to take defensive actions more quickly. A SIM system collects data into a central repository for trend analysis and provides automated reporting for compliance and centralised reporting.