Trust Flow and Citation Flow are proprietary metrics created by Majestic.com in 2012, and now used as industry standard metrics to measure the health of any given URL's link profile.
Both flow metrics can be applied to any URL, root domain, or sub-domain.
The calculations used to create these metrics are complex, but in general, they can be defined as follows:
Citation Flow: A measure of how influential a URL might be based on how many sites link to it. (AKA Link Quantity)
Trust Flow: A measure of how influential a URL might be based on the quality and authority of the sites that link to it. (AKA Link Quality)
AgencyAnalytics simply reports the Flow metrics that we receive from Majestic. We have no ability to recalculate, contest, appeal, or modify the Flow metrics that we receive.
Learn more about Trust Flow and Citation Flow at the following links:
Majestic's initial announcement and explanation of their flow metrics from 2012
Using Majestic Citation Flow and Trust Flow to check the Quality of your Link Prospects (Another post from Majestic's blog)
Citation Flow vs Trust Flow, what is it? (Brief, succinct definition from a 3rd party blog)