Difference between "genmask" and "netmask"?

https://segmentfault.com/a/1190000019363010

https://serverfault.com/questions/696988/difference-between-genmask-and-netmask

https://zhuanlan.zhihu.com/p/61805945

https://www.gitdig.com/post/2019-05-18-route-command/