Understanding the Difference Between Proxy and Reverse Proxy
Tags: webdev, networking, dotnet, dotnetcore
Published: 2024-03-22 10:52:19

Hey guys!

If you are working in the web architecture, _proxies and reverse proxies_ play vital roles in facilitating communication between clients and servers. Despite sharing similar concepts, they serve distinct purposes and have different functionalities. 
There is some confusion around this two concepts. 
Let's put in the table the definitions.

**Proxy:**

A proxy server acts as an intermediary between a client and a server. When a client sends a request to access a resource, it doesn't directly communicate with the target server; instead, it communicates with the proxy server. The proxy server then forwards the request to the target server on behalf of the client. Upon receiving the response from the server, the proxy server sends it back to the client.


**Key Characteristics of a Proxy:**

1. **Client-Side Proxy:** Proxies primarily operate on the client side, intercepting requests before they reach the destination server.
2. **Anonymity and Security:** Proxies can enhance security and privacy by masking the client's IP address and providing anonymity.
3. **Caching:** Proxies can cache frequently accessed resources, improving performance by serving cached content to clients without needing to fetch it from the server every time.
4. **Content Filtering:** Proxies can filter content based on predefined rules, allowing organizations to control access to specific websites or content categories.

**Reverse Proxy:**

A reverse proxy, on the other hand, sits between the internet and web servers, forwarding client requests to the appropriate backend servers. Unlike a regular proxy, which forwards requests from clients to servers, a reverse proxy receives requests from clients and directs them to the appropriate backend server based on factors like load balancing, content caching, or other criteria.

**Key Characteristics of a Reverse Proxy:**

1. **Server-Side Proxy:** Reverse proxies operate on the server side, intercepting requests before they reach the destination servers.
2. **Load Balancing:** Reverse proxies distribute client requests across multiple servers, balancing the load and ensuring efficient resource utilization.
3. **SSL Termination:** Reverse proxies can handle SSL/TLS encryption and decryption, relieving backend servers of this resource-intensive task.
4. **Content Caching:** Similar to regular proxies, reverse proxies can cache content to improve performance and reduce the load on backend servers.

**Key Differences:**

1. **Direction of Traffic:** Proxies intercept client requests, while reverse proxies intercept requests before they reach backend servers.
2. **Location:** Proxies are typically deployed on the client side, while reverse proxies are deployed on the server side.
3. **Functionality:** Proxies focus on client-side tasks like anonymity, caching, and content filtering, whereas reverse proxies handle server-side tasks like load balancing, SSL termination, and content caching.

In conclusion, while both proxies and reverse proxies act as intermediaries in network communication, they serve different purposes and operate at different points in the client-server interaction. Understanding these distinctions is crucial for designing robust and efficient network architectures.

In a scenario of the web development you will work a lot with reverse proxy or API Gateway. A common package in .net is Ocelot library that make it possible create in a easy way API Gateways for your projects. 
Stay tune! In the next article I will write about API Gateways and Ocelot.