It depends.  If you want to become a citizen developer, capable of doing more things with less code for your organization, both is the best approach.  However, if you're try to choose between the two, use the below guidance:Canvas AppsThese are the "flashy" fun apps a lot of people are talking about these days.  These are the ones most often associated with low/no code environments, and they're great because they can connect to Microsoft and non-Microsoft data sources.Users have control over the appearance and design of these apps.  These apps are great for non-technical users who need to interact with data easily.Model AppsWhile not as flashy, model-driven apps are better suited for more complex business applications.  These apps are built off the Dynamics 365 framework, and the user experience will be reflective of this.  These apps use the Common Data Service (CDS) as the data source.When it comes to enhancing a Dynamics 365 environment, these are often the apps leaned on.  There is less control of the appearance and design for these apps, and therefore, the UX will feel much like that of Dynamics 365.