If you wish to install a program or package to your Zorin OS machine using the package managers please follow this guide:
1. Go to either the Software Center (Start > Software Center) or Synaptic Package Manager (Start > Package Manager). Use the Software Center for installing programs easily (for beginners) and Synaptic for installing system files, libraries and programs (for advanced users).
2. Search for the application using the search option or browse by category.
3. Double click on the program and click install or remove and enter your password (in the Software Center) or click on the check box and press the desired option (in Synaptic).
4. Then press apply (only in Synaptic).
5. Close out when all the changes have been made.