Automation

What is the difference between Juniper Ansible modules junipernetworks.junos.junos_package and juniper.device.software? And which one should be used for Juniper upgrades of network devices?  

Between the Ansible maintained collection, junipernetworks.junos, and the Juniper maintained collection, juniper.device, I am always going to start with the Juniper maintained one. (I work at Juniper, but I give reasons beyond knowing the developers below.) Pre 2.10, I completely understood why people used the Ansible ones as they were in Ansible Base by default and had been tested more recently. But since the move to Ansible Core, I would always recommend the Juniper ones for these reasons:
- Built with Junos best practices
- Regression tested with Junos OS and Junos Evolved
- Additional configuration formats.. do the Ansible ones support XML, JSON, and set yet? 
- Pre and post check support
As a reminder, the files are not all compatible between collections, so there are differences if you want create separate playbooks to test with both. 

TL; DR I would use these juniper.device modules

What is the difference between Juniper Ansible modules junipernetworks.junos.junos_package and juniper.device.software? And which one should be used for Juniper upgrades of network devices?