Virtual environments are self-contained directories that contain a Python installation for a particular version of Python, plus additional packages. They help separate project-specific dependencies by creating isolated spaces, ensuring each project has its own set of dependencies without conflicts with other projects. Virtual environments allow developers to work on multiple Python projects without worrying about interdependencies and provide an isolated space where they can install Python and other packages, making their projects reproducible. There are several tools available for creating virtual environments, including venv, virtualenv, and pipenv. Venv is a built-in Python module that creates virtual environments, which are essential for isolating project-specific dependencies and maintaining clean development ecosystems. Docker containers also provide consistency, isolation, and reproducibility in development, making them beneficial for Python development. Snyk is a tool that helps find and fix security vulnerabilities in Docker images, ensuring they are secure before deployment.