What are the merits and demerits of using iframe into Salesforce lightning experience?

Hi Abhay,

While it is possible to use an iframe in the visualforce page and lightning component, Salesforce strongly recommends avoiding this. Visualforce pages are wrapped in their own iframe when displayed in Lightning Experience. If you use an iframe in the visualforce page it will add an additional level to the iframe that increases the complexity of the environment.Also, it will be difficult to debug an issue. If we talk about merits then I will say you don't need to write additional code to remove the iframe for the existing functionality. If you want more detail then go through the document  .

Thanks.