> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Section Introduction
> Overview of service mesh fundamentals and how Cilium uses eBPF, Envoy integration, and components like Hubble to provide traffic management, security, observability, and policy enforcement
In this lesson we'll cover two focused areas:
* What a service mesh is and the core concepts behind it (traffic management, security, observability, and policy).
* How Cilium implements service-mesh capabilities — the architecture, underlying technologies (notably eBPF), and the key features that make Cilium suited for modern microservices environments.
This lesson assumes familiarity with Kubernetes and basic networking concepts. If you're new to Kubernetes, start with the [Kubernetes Basics](https://kubernetes.io/docs/concepts/overview/what-is-kubernetes/) guide. For hands-on Cilium material, see the [Cilium documentation](https://cilium.io/docs/).
What you'll learn:
| Topic | Why it matters | Outcome |
| ------------------------- | -------------------------------------------------------------------------- | --------------------------------------------------------------------------- |
| Service mesh fundamentals | Understand the problems service meshes solve in microservice architectures | Be able to explain traffic control, mTLS, and observability concepts |
| Cilium architecture | Learn how Cilium uses eBPF and integrates with proxies | Understand Cilium's design tradeoffs and how it enforces policies |
| Key features & components | Compare traffic management, security, and monitoring features | Know which Cilium components (e.g., Hubble, Envoy integration) are involved |
Core concepts covered (brief):
* Traffic management: routing, retries, circuit breaking, L7 vs L4 control.
* Security: identity, mTLS, and authorization policies.
* Observability: distributed tracing, flow visibility, metrics and logs.
* Policy enforcement & performance: how kernel-level technologies improve policy performance.
Helpful references:
* [Cilium — eBPF-based networking and security](https://cilium.io/)
* [Hubble — observability for Cilium](https://cilium.io/docs/concepts/hubble/)
* [Envoy Proxy](https://www.envoyproxy.io/)
* [eBPF overview](https://ebpf.io/)
In the sections that follow we'll expand each concept and map it to Cilium's components and architecture, so you can see both the theoretical and implementation sides of a service mesh.