Question 1

What is the difference between a reverse proxy and a load balancer?

Accepted Answer

Considerable overlap, and a real distinction: a **reverse proxy** sits in front of servers and handles requests on their behalf; a **load balancer** distributes requests across several servers. Most modern software does both, which is why the terms blur.

**Forward proxy vs reverse proxy**, first, because this trips people up:

**A forward proxy** acts on behalf of **clients**, sitting between users and the internet — corporate web filtering, for example.

**A reverse proxy** acts on behalf of **servers**, sitting between the internet and your infrastructure. Clients believe they are talking to the real server.

**What a reverse proxy does beyond forwarding:**

**TLS termination**, so certificates are managed in one place rather than on every backend.

**Caching** of responses.

**Compression.**

**Request routing** by path or hostname, so one address serves several applications.

**Hiding internal structure**, so backend addresses and software are not exposed.

**Authentication and rate limiting** applied centrally.

**What a load balancer adds:**

**Distribution algorithms** — round robin, least connections, weighted, or hashing on a client attribute.

**Health checks**, removing failed backends from rotation automatically. **This is the feature that actually matters**, and it is what makes a load balancer a resilience tool rather than merely a distribution one.

**Session persistence** (sticky sessions), keeping a user on the same backend where the application requires it.

**Layer 4 vs layer 7.** A **layer 4** load balancer works at TCP level — fast, protocol-agnostic, and blind to content. A **layer 7** balancer understands HTTP and can route on paths, headers and cookies, at some cost in overhead. A reverse proxy is inherently layer 7.

**Where each fits:** a reverse proxy alone in front of a single application server is common and useful; a load balancer is needed once there is more than one backend or uptime requires removing a failed one automatically.

**Common implementations** — nginx, HAProxy, Traefik, Envoy and cloud-managed services — mostly perform both roles, which is why the labels are used interchangeably in practice.

**Note that a load balancer is itself a single point of failure** unless deployed redundantly, which is the mistake worth avoiding.

Question 2

What is the difference between a proxy and a VPN?

Accepted Answer

A proxy intercepts traffic for a specific application; a VPN captures traffic from the whole device and encrypts it. The practical difference is scope and encryption, and confusing the two leads

Question 3

How is internet filtering and censorship actually implemented?

Accepted Answer

Through several techniques operating at different layers, each with different costs, different accuracy and different ease of circumvention — and most real systems combine them. The techniques, in

Question 4

What are peering and transit?

Accepted Answer

The two ways networks connect to each other — and the distinction is essentially who pays whom. The internet is a network of networks. No single organisation runs it. Around a hundred thousand

Question 5

What is DNS over HTTPS, and should I use it?

Accepted Answer

DNS over HTTPS (DoH) encrypts your DNS queries so that whoever carries your traffic cannot read which sites you are looking up. It closes a genuine privacy gap and shifts trust rather than

Question 6

Who issues SSL certificates, and what do they actually prove?

Accepted Answer

A certificate authority (CA) issues them, and what most certificates prove is narrower than people assume: control of the domain name, and nothing else. What a certificate contains. The domain name

Question 7

What is NAT, and why does every home network use it?

Accepted Answer

Network Address Translation lets many devices share one public IP address, by rewriting addresses and ports as traffic passes through the router. Why it exists. IPv4 provides around 4.3 billion

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