Data Execution Prevention (DEP) is a security feature in modern operating systems that helps protect against malicious attacks. It works by marking certain areas of memory as non-executable, meaning that code cannot run from those areas. This helps prevent harmful software from executing and causing damage to the system. DEP can be applied to both hardware and software. When enabled, it monitors applications and processes to ensure they do not execute code from protected memory regions. This adds an extra layer of security, making it more difficult for attackers to exploit vulnerabilities in software and gain unauthorized access to a computer.