The amount of amplification that a preamp provides is known as its "Gain" and is measured in Decibels. It is fairly typical for a specification sheet of an audio interface to provide the maximum gain figure of a pre-amp, so that you can check that the interface will provide enough gain to fully amplify the signals that you wish to feed into it.
There are two ways in which gain can be applied to a signal, in the analogue domain, or in the digital Domain.
For example, on the Audient iD24, you can add up to 58dB of gain in the Analogue domain using the iD24's Audient Console Mic Preamp. There is then also a further +10dB boost that can be added to the signal in the Digital domain via the button in the iD mixer application.
This gives a total of 68dB of gain available to the inputs on iD24.
On our website and communications, we will typically provide the total gain figure; however, in our detailed specifications, found in our manuals or on our helpdesk, we will show the analogue gain and digital gain figures separately to provide total clarity on how our inputs work.
If you need any clarification regarding this, please do not hesitate to contact our support team, who will be happy to assist you further.