Blockchain security involves protecting blockchain networks and applications from threats such as 51% attacks, smart contract vulnerabilities, and phishing. It uses cryptographic principles, consensus mechanisms, and decentralized architecture to ensure data integrity, transparency, and resistance to tampering.

Cloud computing is the delivery of computing services—like servers, storage, and software—over the internet. It allows users to access and manage data remotely, scale resources on demand, and reduce infrastructure costs. Common models include IaaS, PaaS, and SaaS. Cloud computing supports flexibility, collaboration, and digital innovation across various industries.

DevOps best practices focus on automating workflows, enhancing collaboration between development and operations teams, and delivering software faster and more reliably. Key practices include continuous integration and delivery (CI/CD), infrastructure as code, automated testing, monitoring, and rapid feedback loops. These practices help improve efficiency, scalability, and system stability.

Application security focuses on protecting software from vulnerabilities and threats throughout its lifecycle. Best practices include input validation, authentication, access control, secure coding, and regular security testing to prevent attacks like SQL injection and cross-site scripting (XSS).

Ethical hacking involves legally testing systems for vulnerabilities to strengthen security. Techniques include penetration testing, social engineering, network scanning, and exploiting known weaknesses—helping organizations identify and fix security flaws before attackers do.