AEM Static Templates
Static templates are created by developers ( It defines page rendering component , availability of template for authors to create the page )
Stored in /apps directory of CRX
Once a page is created using templates, after that if we make any change in static template it wouldn't affect the page.
Design mode is available for applying Page design.
AEM Editable Templates
Editable Templates can be created by template-authors ( non-developers ).
Stored in /conf directory of CRX
Pages created using editable templates would affect if any changes on editable templates are done.
Page design is controlled by content and page policies.Hence no design mode available.
Source :- AEM Static Template Vs Editable Template
Also Do watch :- Template Editor Enhancements in AEM 6.3
Really Nice Community work!! Keep them sharing with community
~kautuk
Kautuk Sahni