When I try to add data in arcmap some of the files in my folders can't literally be viewed

[ImeldaAmuron]

Hello guys. It's nice that there's a platform like this. I am a student and I have a question. When I try to add data in arcmap some of the files in my folders can't literally be viewed. What could be the cause.

[ImeldaAmuron]

Hey, the files am adding are adf files.

[DavidPike]

arcmap preferences are set to restrict visible filetypes to those that can generally be added into/viewed via the program.

no idea about adf files, but:

In the catalog pane in arcmap, the farmost right icon at the top is the catalog options, click on that. 

go to file types tab, new type, then add the extension.

[sabahfree]

Hello, this is the first time that I enter into the conversation with the members of the company (ESRI). In fact, I wanted to comment on the course of dealing with satellite images and visuals in the GIS environment, which started today 11/8 and was very useful, the most important weakness that we professors suffer from In the Arab countries, there are few sources that speak and explain satellite visuals, and therefore we suffer from difficulty in applying it in many vital applications, so registering and entering such courses are very useful. Thank you very much,
Assistant teacher Sabah Omar

[sabahfree]

What is meant by adf files?