Dynamics 365 CE has a native security model that is based on users having various degrees of layered access to the application. This access is governed primarily using security roles assigned to users that refer to an access level with specific privileges. These privileges specify what a user can do on those records normally relative to the owner of the record and can be influenced by the corresponding business unit they are part of.
Often, security within the Dynamics 365 CE application is summarized as having role, record, and field access. This is a good summary of the levels ...
