dataloader.io: How Column Order Is Determined

In dataloader.io from MuleSoft, the order of columns in exported CSV files depends on how fields are arranged in the Query Builder or defined in a custom SOQL query.

When using Query Builder with Batch API.

• The column's order in a CSV file is defined by the order in which the objects are listed in the Query Builder (The fields on the left side of the Query Builder’s UI under the title 'Fields'). 
• The column's headers are returned as field labels. 

When using Query Builder with Bulk API.

• The column's order in a CSV file is defined by the order in which the objects are listed in the Query Builder (The fields on the left side of the Query Builder’s UI under the title 'Fields'). 
• The column's headers are returned as API Names.

When using a Custom SOQL

• The column's order in a CSV can be changed by customizing SOQL query. 
• The headers are returned as API Names (not field labels).