Access to the sudoers file.

Hello,

The answer to your question is Yes. It is accessible only from Admin (at Linux is root) user only.

Read here[1] more about this special file

[1] - https://help.ubuntu.com/community/Sudoers

Regards
 NikTh

Yes or their would be zero system security and any user would be able to promote themselves and run riot on the system.

Does this mean that only administrators can use the sudo command? E.g.

sudo apt-get install synaptic

responds with

{user} is not in the sudoers file. This incident will be reported.

User is standard, not administrator.

Yes @Robert Joyce, only administrator can use sudo command.

Regards
 NikTh

Yes, root can also use sudo buts it's not necessary. Only users in the sudo group can use sudo, you can use command aliases and groups to further control them. So, for example, a user may be in the so group but only granted access to the apt-get command and nothing more.