Pending or Processing?
Pending means that your e-filed return is on its way and that the government hasn't accepted or rejected it yet.
Processing means the tax return has been Accepted (received) by the IRS is currently being processed.
After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website.