Assessment types are used in JumpRope mainly as the vehicle that assigns weight to an assessment.
Depending on the settings that have been selected, teachers may or may not be able to manage their own assessment types and weights.
Administrators can choose to create a locked set of types and weights or they can allow teachers to edit their own types and weights for use in their own gradebooks.
A common assessment type model used by many JumpRope schools is the Formative/Summative model. In this setup, there are only two types available to teachers and their respective weights are also managed by administration. Generally, the Formative type is assigned a nominal weight like 0.1 and the Summative 1.0. These allow for Formative assessments to be reported on student mastery reports but to not carry much sway in an overall score, especially once a Summative score or two are entered.
Other models are more traditional and use common types like Test, Classwork, Paper, etc.
See here for more information on how teachers can manage their own custom assessment types if the feature is enabled.
See here for more information on how administrators can setup their assessment types.