Facebook tracks orders coming from people either clicking the ads or seeing the ads. Both metrics are important, and Facebook combines the two into one metric for a total number of orders.
Click orders occur when a user is shown your ad, clicks on it and converts (this can be a purchase, lead, etc. – whatever your conversion goal is).
View orders occur when a user is shown your ad (an impression), they do not click on it, but they later visit your store and converts. This is why you’ll sometimes see that your number of conversions could even be higher than your number of clicks—people don’t need to click to convert in Facebook’s default reporting.
Please Note: The default attribution setting for store's using Vantage is 28 day for clicks and 7 day for views.