a problem about the configuration of caching

[CoolSpring8]

Hello! Well,there are two lines in config/nginx.d/default.conf.erb,which are " # avoid caching by proxies add_header Cache-Control private;" As far as I know,this header prevents files(even if they are static) from being cached by both proxies and client browser.It might reduce the chances of some problems,but it also makes the website slower to be loaded. So,Is it necessary for a production environment? I removed these lines in my application,and it has been working well so far. I'd like to thank you for answering me.