eBPF (Extended Berkeley Packet Filter) is a technology that creates a sandbox environment allowing bytecode programs to run in the core of an OS kernel without modifying or changing the default behavior of the kernel. eBPF was created to prevent needless packet transfers from the kernel space to the user space, and it works by accessing a program written in some kind of language, compiling it into bytecode, attaching it to a specified hook, and loading it into the kernel. The verifier checks the bytecode for security and assurance compliance before execution, and the Just-In-Time (JIT) compiler compiles the bytecode into native machine code for stronger execution speed. eBPF can be used for resource management, networking, security, observability, and debugging, providing a safe environment for programs to execute without affecting the kernel. However, it may not be suitable for use cases requiring more flexibility and control over program execution, and alternatives like Iptables, SystemTap, and LTTng exist for specific tasks. eBPF is a powerful tool for extracting metrics from the kernel without modifying or breaking the kernel itself, making it an attractive option for certain use cases.