The reference materials are:
https://blog.csdn.net/qq_24394093/article/details/89401180 Three methods of installing software in Linux system
https://www.cnblogs.com/heshouhui/p/9672611.html Software under Linux Several ways to install
In the first blog, the three ways of execution commands are written in detail, the system is Centos; in the second blog, the directory is explained more clearly.
Understand by yourself:
rpm is suitable for all environments, yum needs to build a local yum source before it can be used;
rpm is a low-level management tool, and yum is an upper-level management tool, which automatically solves dependency package problems.