id:tldr:50966

The command "id ${username}" is used to display the user and group information of a specific user in a Unix-like operating system.

Here is how the command works:

1. The command "id" is used to retrieve information about a user or a group.
2. ${username} is a placeholder for the actual username that you want to retrieve the information for. You need to replace ${username} with the actual username, without the dollar sign ($). For example, if you want to get the information for the user "john", you would replace ${username} with "john", resulting in the command "id john".

When you run the command "id ${username}", it will return information about the specified user, including the user ID (UID), group ID (GID), and supplementary group IDs. Additionally, it may display the username, home directory, and login shell associated with the user.