When backing up your Salesforce data, Gearset uses a variety of strategies from run to run. This aims to balance a number of factors, including speed, accuracy, efficient use of API calls, nuances of behavior for some Salesforce objects and more.
Regardless of the strategy employed by Gearset on any given run, the entire state of the org at that point in time is captured. Every single run can be used to search, view, export and restore all records.
A number of backup solutions will use terminology like "full backup", "synthetic full backup", "incremental backup" to describe differences in the fidelity of data captured on a given run. Depending on the specific implementation, these terms have very different implications from solution to solution. Gearset's backup engine operates in a way that means these terms don't apply.