Does iTunes Backups Happen Automatically? Apple offers very little iCloud storage and I am finding it quite difficult to backup both my iPad and iPhone.

I have set up my iPhone and iPad to sync wirelessly to my MacBook. Now every time they're connected to the same wifi, both my iPad and iPhone show up in Finder under the Locations section. From there I can press the "Back Up Now" button to back the device up via iTunes.

Does this happen automatically, just like iCloud backups? And what conditions do I need to meet in order for this to happen automatically (i.e. the iPhone/iPad needs to be connected to power)?
You need to set up iTunes to allow you to do the backup over WiFi and you need to sync the two devices at least once. After that you should be able to do it, provided;


Both devices must be on the same WiFi network
iTunes must be open on the Mac 
The iOS device must be charging