[A.] Master Record Assessments are used for basic, two-level linked assessments, where any related registers used in the assessment link directly to the Master register. This type of assessment is used for simpler data gathering. 

In the example below, you can see that all related registers link directly to the Processing Activity Register. 

[B.] Non-Master Record Assessments are used for more complex, three-level linked assessments, which can have multiple primary records and registers. For example, you may want to use a Non-Master Record Assessment-type for more complex and granular data gathering (typically using the Processing Event Register) to discover what items of Personal Data are being transferred between particular business areas or to third parties. Example below:

The main visual difference between the two assessment types is that Master Record Assessments allow administrators to select one Master (Primary) Register and display any of its register fields throughout the assessment, rather than showing them in a single pop-up model as seen in Non-Master Record Assessments. 

Master Record Assessments also allow question logic to be applied to register fields, which means respondents can be presented with questions that they only need to complete, depending on the questions they've answered previously in an assessment.

Please see below for a feature comparison table between Master Record and Non-Master Record Assessments: