Secure enclaves use hardware-based isolation techniques to ensure that sensitive computations and data can be processed in an environment that is resistant to tampering and invasive attacks. They encapsulate applications and their data together, which minimizes the risk of exposure to malware and vulnerabilities associated with the operating system, hypervisor, and other applications running on the same system. By creating a secure area within the main processor or memory, secure enclaves allow for protected execution of code and safeguarding of encryption keys and sensitive information.