This article talks about the Ubuntu user system and its basic commands.
For more on this subject, please refer to the SOC Table of Contents.
Because Ubuntu is a multi-user system, we can create different user accounts for different users. The main reason is to make it easier for the administrator to control the different accounts, to control the permissions each user has, as well as giving users a more secure protection.
There are three types of users in total:
- The user first created while installing Ubuntu. This user has more permissions than other users that were created afterwards and can do more.
- The root user. This user is the system administrator and has all of the permissions.
- The normal users. These users are created after the system was installed.
Of the three types of users, each user has their own ID, called UID. The operating system uses the UID to determine which user is which. Detailed user information can be found in the /etc/passwd/ file. We can do this by executing the cat command to open the file like so:
We can see that there are two numbers after each username, such as 0:0 after root and 1000:1000 after ubuntu. The first number is the user’s ID, while the latter is the user’s GID (Group ID). Each user inside the Ubuntu system is grouped within a user group, which is a group of users with the same properties.