# Proxy server

A proxy server is an intermediary machine that receives a client's request, forwards it to the destination under the proxy's own IP address, and relays the response back. The destination sees the proxy, not the client, which is what makes proxies useful for changing apparent location, distributing traffic across many addresses and keeping a stable exit for a session.


## How a proxy works

Your client opens a connection to the proxy, states the destination (a `CONNECT host:port` for HTTPS, or the full URL for plain HTTP), and the proxy opens its own connection to that destination. Everything that follows is copied byte for byte in both directions. TLS still runs end to end between your client and the website: a well-behaved proxy never decrypts it.


## What changes for the destination

- The source IP address is the proxy's exit address, with its geolocation, its provider and its reputation.
- The TCP path is longer, so latency grows by the distance between you, the proxy and the target.
- Nothing else changes unless the proxy adds headers. A transparent corporate proxy may add `Via` or `X-Forwarded-For`; a proxy meant for privacy adds nothing.


## Forward, reverse, and what proxy providers sell

A **forward proxy** sits in front of clients and speaks to many destinations; this is what proxy providers sell. A **reverse proxy** sits in front of servers and receives traffic on their behalf (load balancers, CDNs). Commercial proxy networks differ mainly by where the exit address lives: a household ([residential](https://proxshift.com/glossary/residential-proxy)), a consumer ISP block hosted in a facility ([ISP](https://proxshift.com/glossary/isp-proxy)), a hosting range ([datacenter](https://proxshift.com/glossary/datacenter-proxy)) or a cellular carrier ([mobile](https://proxshift.com/glossary/mobile-proxy)).


## How it works at ProxShift

ProxShift runs forward proxies of all four kinds behind two gateways (res.proxshift.com and mob.proxshift.com on ports 9000 and 9001) and as dedicated ip:port addresses. The gateway never terminates TLS, strips proxy headers and adds none.

## Questions

**Is a proxy the same as a VPN?**

No. A VPN tunnels all traffic of a device at the network layer; a proxy is configured per application or per request and only carries what you send through it. Proxies are the tool when you need many addresses, per-request location changes or thousands of parallel connections.

**Does a proxy hide my identity?**

It hides your IP address from the destination. It does not change cookies, browser fingerprints or account logins; those must be handled separately.

Source: https://proxshift.com/glossary/proxy-server