What Is a Proxy Server and How Does It Work?

A proxy server is a middle layer between your device and the rest of the internet. When you connect through a proxy, the websites you visit see the proxy’s IP address instead of yours. The proxy receives your request, forwards it to the destination, gets the response back, and returns it to you. From the destination’s perspective, the proxy is the visitor.

That sounds simple, and the basic flow is. Where it gets interesting is the why — the reasons people route traffic through a proxy — and the trade-offs between the different kinds of proxies you can use.

How a proxy request actually flows

Skip the proxy and a normal HTTPS request looks roughly like this: your browser opens a TCP connection to www.example.com on port 443, negotiates TLS, sends an HTTP request, and reads the response. The destination server sees your real IP address as the connection’s source.

Add an HTTP proxy and the picture changes:

1. Your browser opens a TCP connection to the proxy instead of the destination.
2. For HTTPS, the browser sends a CONNECT www.example.com:443 request to the proxy.
3. The proxy opens its own TCP connection to www.example.com on your behalf.
4. The browser and the destination negotiate TLS through the proxy’s tunnel; the proxy itself does not see the decrypted traffic.
5. The destination server logs the proxy’s IP as the source — not yours.

For plain HTTP (without the S), the proxy does see the request and response in cleartext. That is one reason HTTPS matters even when you trust the proxy.

Why people use proxies

The reasons cluster into a few common buckets:

• Web scraping and crawling. A single IP making thousands of requests gets rate-limited or banned within minutes. A pool of proxies distributes the load so target sites see normal-looking traffic instead of one hammer. This is the largest commercial use case for proxies. See our web scraping use case.
• SEO and SERP monitoring. Search results are personalized by IP geolocation. To check rankings as a user in Madrid or Milan, you need an IP in Madrid or Milan. SEO monitoring is one of the most common proxy uses after scraping.
• Account management at scale. Platforms detect multi-accounting via shared IP signals. Dedicated proxies give each account its own consistent IP, so the platform sees them as separate users. More on account management.
• Privacy and IP masking. Hiding your real IP from sites you visit is the original use case — older than the commercial-data use cases above.
• Geo-restricted content access. If a service is only available in certain countries, an IP in those countries is the most common way to reach it.

The main types of proxies you will encounter

Proxies are sold along three independent axes. Understanding all three avoids buying the wrong tool.

Protocol: HTTP/HTTPS vs SOCKS

HTTP proxies (which also handle HTTPS via the CONNECT method above) are the most common. They speak the same protocol your browser already speaks. SOCKS proxies operate at a lower level and can carry any TCP traffic — useful for non-HTTP applications like SSH, BitTorrent, or game clients. For browser and scraping work, HTTP(S) is what you want, and what we sell.

IP source: Datacenter vs residential

Datacenter proxies are hosted in commercial datacenters. They are fast, cheap, and reliable. The trade-off is that their IP ranges are publicly known, so anti-bot platforms can flag them as datacenter IPs if they look. Residential proxies route through real consumer ISPs (your neighbor’s home internet, roughly). They are much harder to detect but several times more expensive and slower. Datacenter is the right default for the majority of workloads; residential is the tool when datacenter gets blocked.

Sharing: Private vs shared

A private proxy is assigned to one customer. A shared proxy is used by several customers at once. Private costs more and gives you predictable performance and clean IP reputation. Shared costs less and is fine when the workload tolerates noisy neighbors — bulk SEO checks, link verification, public-data scraping.

Anonymity levels: transparent, anonymous, elite

Even within HTTP proxies there are three sub-categories based on what the proxy reveals about the original request:

• Transparent. Forwards your real IP in the X-Forwarded-For header. The destination sees both the proxy and your real address. Useless for privacy.
• Anonymous. Does not forward your real IP, but does identify itself as a proxy via standard headers. The destination knows traffic is coming through a proxy.
• Elite. Does not forward your real IP and does not identify itself as a proxy. The destination sees what looks like a direct request from the proxy’s IP.

Elite is the standard for serious commercial use. Anything less leaks information that defeats most of the reasons to use a proxy in the first place. All EZProxies plans are elite by default.

What this means for picking a plan

Most workloads need elite HTTP(S) datacenter proxies. The choice between private and shared comes down to whether your target sites care about IP reputation. The choice between USA and our Spain or Italy locations depends on whether you need IP geolocation in those countries.

If you are still trying to figure out which one fits your workload, the use-case pages walk through the most common scenarios with specific recommendations.