What should a CSV file contain?

[Adam-Albu]

What should a CSV file contain? I've got one already and it looks like this:
input,target
1,2
2,3
3,4
4,5
5,6

But it's giving me a parse error. Am I doing something wrong or is a system error?

[LemonFoxmere]

Can you provide some more details about the parse error? And also just on a side note: your input and output data should be on separate CSV files. The input CSV should be uploaded to the input node, and the output CSV to the output node.