PAR Levels and Alerts serve two different functions, although they are similar and can work together.
It's best to think of them as commands:
PAR Level — Once the product quantity goes to x quantity or below, it's low enough to re-order on the next Purchase Order.
Alert — Simply get notified when this product goes below this threshold so that you can replenish quantities ASAP.
The Low Inventory Report includes items at or below your established PAR and/or Alert levels.
This is a visual representation of the different levels:
Opt into receiving e-mails when an item falls below your set PAR level. Navigate to User Settings and activate the toggle as shown below:
Other Differences
Since alerts trigger emails, each user manages their own. Alerts do not and cannot be applied to all users simultaneously.
PAR Levels are applied to the variants themselves, so these are the same for all users.