When a person who is a verified customer of amazon will buy directly product without any discount, the purchase will be verified purchase and its review will be verified review and the unverified reviews are of those customer which don’t purchase directly from amazon marketplace.
An “Amazon Verified Purchase” review signifies that the reviewer made their purchase from Amazon. Additionally, it indicates that they paid the item’s full price without receiving a discount. Unverified reviews signify that the reviewers did not actually buy the product from Amazon.com.