A list of packages and their repositories is stored in your Linux Machine and it can be viewed from :

• packages for Linux
• cat  /etc/apt/sources.list

Before you upgrade your packages or install an important package, it's a good practice to update this list of repositories:

• sudo apt-get update
• This will update package source.list

To physically update your packages you want to use the upgrade command:

• sudo apt-get upgrade
• will physically update packages based on the source.list file we created above

man apt-get to view tons of package functionalities within Linux

sudo apt-get autoremove will remove packages that are no longer required

To Install a new package, you can use:

sudo apt-get install package

e.g

 sudo apt-get install finger