1. Kernel: The kernel is the heart of an operating system, acting as a bridge between hardware and software. It handles essential tasks such as managing memory, running programs, and facilitating communication between components.

2. Linux: Linux is an operating system that is built around the Linux kernel. It includes a wide range of software and applications, making it a complete and versatile OS used in various devices, from computers to smartphones.

3. Linux is known for its security advantages, claiming to be entirely immune to malware would be inaccurate. Linux systems can still be vulnerable to malicious software, but their security is bolstered by factors like its open-source nature, prompt updates, and strong user permission management.