Why is it that with apache configured on my server, I can open the localhost web page on the server, but cannot open it through the public IP outside?

I configured apache on my server on Tencent Cloud, and then through the desktop Google installed on the server (the server system is ubuntu 14.4), I can open the web page under var/www/html that I replaced. Why can’t I use the public IP outside? access?

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I configured apache on my server on Tencent Cloud, and then through the desktop Google installed on the server (the server system is ubuntu 14.4), I can open the web page under var/www/html that I replaced. Why can’t I use the public IP outside? access?

What is the status of the firewall?