The differences between su – and su on Linux

This post introduces the difference between su – and su.

su - logs you in completely as root, whereas su makes it so you are pretending to be root.

The most obvious example of this is that ~ is root’s home directory if you use su -, but your own home directory if you use su.

Depending on your system, it may also mean differences in prompt, PATH, or history file.

Check here for more detailed discussion (PDF).