Once you've exported a solution from your development sandbox environment, you can import the solution into other environments for testing and to deploy it to production.
You can import a solution from the Maker portal. Select the target environment and then click on the Import button of the toolbar, as shown in the following screenshot:
Clicking on the Import button opens a new window:
You should browse to your local computer and select the solution ZIP file you exported from your source environment before clicking on Next. This checks that the ZIP file is a valid solution file and whether it is managed or unmanaged. If it is unmanaged, you will see the following screen:
When you import an unmanaged solution, all the components in the solution file overwrite the components in the Default solution...