eBPF (extended Berkeley Packet Filter) is a Linux kernel feature that enables the execution of sandboxed programs within kernel space, providing controlled program execution and access to system data without compromising security or efficiency. eBPF expands on the concepts of its predecessor, BPF (Berkeley Packet Filter), by offering a wide array of tools for extending program capabilities and a massive community effort has led to the development of Software Development Kits (SDKs) and tools that ease eBPF program development. eBPF works by allowing developers to execute custom code in kernel space through a verification process, which checks for issues like memory access beyond designated regions. This approach provides flexibility, programmability, efficient resource utilization, enhanced security, and dynamic tracing capabilities, making it suitable for various use cases such as performance monitoring, network observability, security auditing, and more. eBPF is built into the Linux kernel source code of modern versions of Linux and can be used in Kubernetes environments with proper setup and configuration. While eBPF has its limitations, including the need to write custom code that complies with the kernel verifier and potential portability issues across different Linux distributions, it offers a powerful tool for observability, performance monitoring, security auditing, and other tasks.