In cybersecurity, 'proprietary' refers to software, algorithms, or technologies that are owned by an individual or company and are not made publicly available. The source code or design details of proprietary products are typically kept confidential to protect intellectual property and maintain a competitive advantage. Users may be granted licenses to use proprietary solutions, but they cannot modify, share, or distribute them freely. Proprietary systems are contrasted with open-source alternatives, which are developed collaboratively and openly shared. In cybersecurity, relying on proprietary tools can enhance security through obscurity but may also limit transparency and independent security assessments.