Summary

Linux is a multi-user operating system. Linux accounts keep users' work separate from each other, private and protected. All information is organized into files and each file is owned by an account, protected from other accounts. Consequently, you can do nothing on Linux without an account.

All files are owned by an account and by a group. Permission to look at, modify, or run a file is assigned to the user, to the group, and to all users. This system of permission is what protects each user's work and information.

This chapter explains how to do the following:

• Check and change account information, such as username, home directory, and group membership

• Add accounts

• Add or modify passwords. Provides rules for secure passwords

• Add groups

• Set a new root account password

The next chapter explains how to set and change file permissions. It also explains how to create, move, rename, delete, and otherwise manage files.