The Linux kernel is the core part of the Linux operating system, acting as a bridge between the hardware and software. It manages system resources, allowing different programs to run smoothly by coordinating tasks like memory management, process scheduling, and device control. This makes it essential for the overall performance and stability of any system using Linux. Developed by Linus Torvalds in 1991, the Linux kernel is open-source, meaning anyone can view, modify, and distribute its code. This has led to a vast community of developers contributing to its improvement, resulting in various distributions like Ubuntu and Fedora that cater to different user needs and preferences.