认识
官网：https://www.squid-cache.org/
文档：https://www.squid-cache.org/Doc/
仓库：https://www.squid-cache.org/Versions/
Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on most available operating systems, including Windows and is licensed under the GNU GPL. 简而言之，Squid 是个缓存代理，通过缓存文件来降低带宽占用及提高响应速度。
性质
squid-cache wiki / Current Features / https://wiki.squid-cache.org/Features