Cloud computing faces several main challenges, including security risks, such as data breaches and unauthorized access to sensitive information. Downtime can also be problematic, as service outages disrupt operations. Additionally, compliance with regulations such as GDPR and HIPAA requires careful data management and storage policies. Other issues include vendor lock-in, where businesses become reliant on a single cloud provider, and the need for scalability to meet varying demands without compromising performance. Overall, addressing these challenges is essential for maximizing the benefits of cloud computing technologies.