To remove password authentication in the terminal:

To remove password authentication in the terminal:
sudo visudo

Then scroll down using the down arrow key:
Find the root section and add this word before ALL
NOPASSWD:
e.g.:
From this:
root    ALL=(ALL)       ALL
To this:
root    ALL=(ALL)       NOPASSWD: ALL

Then find the %wheel section and add this word before ALL
NOPASSWD:
e.g.:
From this:
%wheel  ALL=(ALL)       ALL
To this:
%wheel  ALL=(ALL)       NOPASSWD: ALL

Therefore save it by using some keywords:
1) CTRL+O (For saving/writing out)
2) Enter key (To save the filename as it is)
3) CTRL+X (To exit)