徇私舞弊发售发票、抵扣税款、出口退税罪，是指税务机关的工作人员违反法律、行政法规的规定，在办理发售发票、抵扣税款、出口退税工作中，徇私舞弊，致使国家利益遭受重大损失的行为。

违法提供出口退税凭证罪，是指其他国家机关工作人员违反国家规定，在提供出口货物报送单、出口收汇核销单等出口退税凭证的工作中，徇私舞弊，致使国家利益遭受重大损失的行为。

相关双语法规：

《刑法》第405条第1款规定：

税务机关的工作人员违反法律、行政法规的规定，在办理发售发票、抵扣税款、出口退税工作中，徇私舞弊，致使国家利益遭受重大损失的，处五年以下有期徒刑或者拘役；致使国家利益遭受特别重大损失的，处五年以上有期徒刑。

Any functionary of a tax authority who, in violation of the provisions of laws and administrative rules and regulations, engages in malpractices for personal gain in the process of selling invoices to offset tax payments for export rebates, thus causing heavy losses to the interests of the state, shall be sentenced to fixed-term imprisonment of not more than five years or criminal detention; If especially heavy losses are caused to the interests of the State, he shall be sentenced to fixed-term imprisonment of not less than five years.

《刑法》第405条第2款规定：

其他国家机关工作人员违反国家规定，在提供出口货物报送单、出口收汇核销单等出口退税凭证的工作中，徇私舞弊，致使国家利益遭受重大损失的，依照前款的规定处罚。

Any functionary of any other State organ who, in violation of State regulations, engages in malpractices for personal gain in the provision of export tax refund documents such as the declaration of export goods and the verification and cancellation of export foreign exchange receipts, thus causing heavy losses to the interests of the State, shall be punished in accordance with the provisions of the preceding paragraph.

第2款中“其他国家机关工作人员”，是指除税务机关工作人员以外，负有对进出口货物检验、出具进出口货物证明的其他国家机关工作人员，如海关、外汇管理部门的工作人员。