The difference between Su and su in the Linux shell __linux

The difference between Su and Su-

The former only switches identities, but the shell environment is still the original user's shell, while the user and the shell environment switch to the new user. The PATH environment variable error will not occur until you switch the shell environment.

Specific cases:
Someone logged in with Root. Then switch to the Oracle user and execute the sqlplus command with an error:? Command not found!
is because of the use of Su, not Su-
There's another obvious difference:
For example, the root user in the/root/directory, Su Oracle,
Switched to an Oracle user, but the directory is still under/root/.
If you use Su-oracle
You can find that the directory also switches to the Oracle user's home directory.