How to comment out multiple lines at once in vim

I'm Ito, an infrastructure engineer.
If you're editing files on Linux, you'll probably use "Vim" most often.

When editing configuration files, you may sometimes want to comment out unnecessary settings or other elements, and
you might want to comment out multiple lines at once.

This time I would like to introduce you to how to do this

Use rectangular selection mode

For operations on multiple lines, use the "Rectangle Selection Mode."

Open the file in vim and enter the following command:

ctrl + v

Enter "Rectangular Visual Mode".
Use the cursor to select the lines you want to comment out.

I (shift + i)

This is "insert mode."

Enter the character to comment out (such as "#")

Esc

Exit insert mode

I've put it all together in GIF

How about that?
A comment has been inserted at the beginning!

Let's try our best to become proficient in Vim