Quick answer: A proxy server is a computer that sits between you and the rest of the internet and forwards your requests on your behalf. Instead of your machine talking directly to a website, it talks to the proxy, and the proxy talks to the website. The website sees the proxy's address, not yours. That single indirection is the basis for everything proxies are used for: privacy, access control, caching, load balancing, and web scraping at scale.
The word "proxy" just means "stand-in." A proxy server stands in for one side of a network conversation. Which side it stands in for is what separates a forward proxy from a reverse proxy, and that distinction is the first thing to get straight.
Forward proxy vs reverse proxy
Both are intermediaries, but they face opposite directions and serve opposite parties.
| Forward proxy | Reverse proxy | |
|---|---|---|
| Sits in front of | The client (you) | The server (a website) |
| Acts on behalf of | The user making requests | The site receiving requests |
| The origin sees | The proxy's IP, not yours | Normal traffic; it is part of the site |
| Typical job | Hide the client, filter outbound traffic, scrape | Load balancing, caching, TLS termination, WAF |
| Who runs it | You, or a proxy provider | The website operator |
A forward proxy is the one people usually mean by "a proxy." You configure your client to route through it. It represents you to the outside world, so the destination sees the proxy instead of you. A corporate network that filters which sites employees can reach is using a forward proxy. A scraper rotating through residential IPs is using forward proxies.
A reverse proxy works the other way. It sits in front of a web server and represents that server to the world. When you load a large website, you are almost certainly hitting a reverse proxy first. It might terminate the encrypted connection, cache popular pages, spread traffic across many backend machines, and block malicious requests before they reach the application. You never configure it; the site operator does.
Common types of forward proxy
When people compare "proxy types" for scraping or privacy, they are almost always comparing forward proxies by where the IP address comes from.
- Datacenter proxies. IPs owned by hosting companies and cloud providers. Fast and cheap, but easy for sites to recognize as non-residential, so they are more likely to be blocked.
- Residential proxies. IPs assigned by internet service providers to real homes. They look like ordinary consumer traffic, so they are far harder to distinguish from a genuine visitor. They cost more and are usually slower.
- Mobile proxies. IPs from cellular carriers. Because many real users share a small pool of carrier IPs, these are the hardest to block, and the most expensive.
- Transparent vs anonymous proxies. A transparent proxy passes along headers that reveal it is a proxy (and sometimes your original IP). An anonymous proxy hides that it is a proxy at all.
For a full breakdown of which proxy type fits which scraping job, see best proxies for web scraping.
Why scrapers use proxies
If you request a few pages from a site, your own IP is fine. Proxies matter when you request many pages, because a single address hammering a server is easy to detect and rate-limit. Scrapers use forward proxies to:
- Distribute requests across many IPs so no single address exceeds a site's per-IP rate limit.
- Appear as ordinary visitors by using residential or mobile IPs that blend in with real traffic.
- Access geo-specific content by routing through an IP in the region whose version of a page they need.
- Keep the origin machine's identity out of the picture, which is standard operational hygiene for any automated system.
A brief note on ethics: proxies are a tool for accessing public data at reasonable volume, not for evading authentication or ignoring a site's rules. Respect robots.txt, keep your request rate polite, and do not use proxies to get around login walls or paywalls. The goal is to be a well-behaved automated visitor, not an abusive one.
Privacy and security basics
Outside of scraping, proxies show up in everyday privacy and security setups. A forward proxy hides your IP from the sites you visit, which is why they are used for basic anonymity and for reaching content restricted by region. On a corporate or school network, an outbound proxy enforces policy: it can block categories of sites, scan traffic for malware, and log where requests go.
Two limits are worth knowing. First, a plain proxy is not a VPN. A VPN encrypts all traffic from your device and routes it through a tunnel; a proxy typically handles a single application's traffic and may not encrypt anything. Second, a proxy you do not control can see your traffic. Only route through proxies you trust, and prefer encrypted (HTTPS) connections end to end.
When you actually need one
You need a proxy when direct requests are not viable. In practice that means:
- You are making enough automated requests that a single IP would get rate-limited or blocked.
- You need to see a site as a visitor from a specific country would.
- You are on a network that requires outbound traffic to go through a gateway.
- You want to keep your origin server's address out of logs on the sites you hit.
For light, occasional requests, a proxy is overhead you do not need. Here is a simple direct fetch, no proxy involved:
import requests
response = requests.get("https://example.com")
print(response.status_code) # 200
That works until the site starts refusing you, at which point you either build and rotate a pool of proxies yourself, or hand the problem to a service that manages it for you.
Letting the proxy layer disappear
Running proxies well is its own project: sourcing reliable IPs, rotating them, retrying failed requests, matching the right proxy type to each target, and handling the sites that render content only after JavaScript runs. Most teams that just want the data would rather not own that infrastructure.
That is the case for a fetch API that handles the proxy layer for you. You send a URL; it selects and rotates the appropriate proxies, renders the page, and returns clean content.
curl https://link.sc/v1/fetch \
-H "Authorization: Bearer lsc_..." \
-H "Content-Type: application/json" \
-d '{"url": "https://example.com", "format": "markdown"}'
You get the page content back as markdown, with the proxy selection, rotation, and rendering managed behind the API. You can read how link.sc approaches this in the docs.
The bottom line
A proxy server is an intermediary that forwards requests. Forward proxies stand in for the client and are what scrapers and privacy tools use; reverse proxies stand in for the server and are what websites run. The main forward-proxy types (datacenter, residential, mobile) trade cost against how hard they are to block. Reach for a proxy when direct requests get blocked, rate-limited, or geo-restricted, and consider a managed fetch layer if you would rather not run the pool yourself.
Want the data without managing a proxy pool? Start free with link.sc and fetch any URL as clean markdown.