The bulk logs are extended version of your results file.
Typically the log file include:
ID: of the bulk upload.
Message_id: the message identification number.
Sku: The sku has been modified
Operation: That field contains what request has been sent to our system
Type: That header will define the nature of the update of that item. Example Inventory(stock), Images(media), Relations(shippng)
Date: Timestamp of the action
Result: The result of that action
Messages: Typically that header will give you value only if the Results are (failure/error)
Example log sheet: