Elements in Dynamics 365 for Operation are the objects that reside in the AOT in the Application Explorer. Elements can be customized once they are added to a specific project or model
A Dynamics 365 for Operation model is a group or collection of elements. A model is a design time concept. A model may contain multiple Visual Studio projects, each containing a subset (or all) of elements from the originating model.
A Dynamics 365 for Operation package is a deployment unit may contain one or more models. In addition to elements, this includes model metadata, which is the descriptive data that defines the properties and behavior of the model. A package can be exported to a file, which can then be deployed into a staging or production environment.
Packages are folders located in the model store folder, as can be seen below:
Model folders are contained in their package folder. Each model folder contains type-specific folders:
A package folder contains a descriptor folder that lists all models that belong to the package. A model descriptor file contains metadata about a model’s properties.