So whats the difference in the file module if I save it as a type of JSON or TEXTFILE? It all really depends on the extension I give it

JSON can not be file type, it is text. File. content can be binary or text. Text is free length and terminated by EOF char at the end. Header of binary file must have info how many bytes are long...

@Zoran Roncevic I was asking what Netsuite indented when they gave the option for

fileType: file.Type.PLAINTEXT

vs

fileType: file.Type.JSON

I am sure 99% that is same ... I wrote about file types in generally, not from NetSuite perspective. All files on the world could be PLAINTEXT or BINARY. Content is something else. You can save your JSON data in file with XML extension or whatever else (JSON, TXT, HTML....). In any case when you READ content you have to know what is inside...