Serial can be imported from the desktop or other 3rd party from the application
Inventory--> Product Serial--> New Product Serial Import
From the above pic, we can see that if you want to import upload product serial, you need to go through the browse option so that you can select the desired file of serial import. Note that the file should be in ".xls " format which is in an Excel format file. In the excel format, the data should be represented as shown in the advanced option like product serial , product name, serial lot number, product serial warranty, product serial_2......... and it goes on depending on how many product serial you are importing or uploading.
This feature of importing serial is provided to reduce the work load as you might have lot of product serials for uploading so doing that in excel format and then uploading in the system will reduce your time and automatically import and generate all the serial of the products along with their name.