Can service definitions and shapefiles be deleted?

[MPach]

After uploading several files to a folder on our portal I'm stuck with a bunch of service definition and shapefile files. 2 questions:

1) What is the actual purpose of each of these files?

2) Can the files be deleted to clean the folder up?

Here's what I'm dealing with and I'd like to clean it up if possible:

[ChadKopplin · Accepted solution]

Yes sir they can, if you are no longer using them in a Map View or Web Map.  

[MPach]

Thank you. Any idea what their exact function is after an upload? 

[Yanlin1]

Just for your backup, the service definition is helped to created hosted content, you can remove them if you want. There is no harm. Feel free to test removing the SD file after the hosted content is created