Dvd?r/?rw

[mailliw]

I know what they mean with + or -, but what does the ? mark mean? What does DVD?R/?RW mean?
Thank You
mailliw

 

[mlurp]

Question Mark.

 

[mlurp]

I'm not being smart just putting a little humor on this. Because I don't know myself. I tried a Google Search and came up blank. Sorry