How do I run a Debian file in Terminal?

Steps to write and execute a script

1. Open the terminal. Go to the directory where you want to create your script.
2. Create a file with . sh extension.
3. Write the script in the file using an editor.
4. Make the script executable with command chmod +x <fileName>.
5. Run the script using ./<fileName>.

What do I do with a .deb file?

deb files, they are designed to primarily handle package names (for example teamviewer, apache2, mariadb etc..) and they retrieve and install . deb archives associated with a package name, from a source specified in the /etc/apt/sources.