What is the difference between reverse proxy and web server?

Question

I read an awesome post on application server vs. webserver at What is the difference between application server and web server?. Moreover, Difference between proxy server and reverse proxy server nicely explains what a proxy server is.

I also learned that some web servers, such as Apache, have reverse proxy built-in. (Source). Also, Wikipedia (https://en.wikipedia.org/wiki/Reverse_proxy) has an image that shows webserver and reverse proxy as separate entities.

Source: https://en.wikipedia.org/wiki/Reverse_proxy (image originally via Privacy Canada, now CC0, license info)

So, I am not sure about the difference between webserver and reverse proxy. Can someone please shed the light?

Ayer

Cloudflare explanation: A reverse proxy is a server that sits in front of web servers and forwards client (e.g. web browser) requests to those web servers. Reverse proxies are typically implemented to help increase security, performance, and reliability. – Symptomatology

Answer 1

A web server listens for HTTP requests and reacts to them by sending back an HTTP response.

A reverse proxy is a web server which determines what response to make by also implementing an HTTP client.

Client A makes an HTTP request to the reverse proxy. The reverse proxy makes an HTTP request to Server B. Server B sends an HTTP response to the reverse proxy. The reverse proxy sends that data as its HTTP response to client A.

Zoophobia

@ Quentin-thank you for help. I am confused. Could you please elaborate on two points: a) webserver listens for HTTP requests and responds by HTTP response b) web server also implements HTTP client. It will be great if you could provide the flow such as (I am assuming...please pardon my ignorance) client --> reverse proxy --> webserver --> app server --> Database. I'd appreciate your thoughts. – Ayer

client --> reverse proxy which is a webserver --> other webserver --> wherever – Zoophobia

Thanks again Quentin. Could you please elaborate on the difference between reverse proxy which is a webserver and other webserver. I understand that one of the differences is relating to reverse proxy server behaving as a client. What other differences exist? I'm curious. – Ayer

@Ayer — There aren't any other differences – Zoophobia