A Wash Sale is where a taxpayer sells securities at a loss, and within a set time frame, purchases the same or equivalent securities thereby recognizing the loss for tax purposes, but engaging in no meaningful economic transaction.
A withholding tax is where the source of income must withhold some of the distribution and remit it to the government; where it is then credited to the taxpayer's account. If the taxpayer's tax liability is less than the amount withheld a refund will be provided.