Understand the difference between personalization and customization in D365FO
Personalization versus Customization
Personalization
Changing the user interface by, for example, adding or removing fields to meet your requirements may be achieved by using the built-in Personalization features of D365FO.
Customization
You have identified a gap in your requirements compared to the out-of-the-box capability of D365FO. The customization is the solution provided by the developer team.