First In, First Out (FIFO)的中文意思为“先进先出法”，指以先购入的存货应先发出(即用于销售或耗用)这样一种存货实物流动假设为前提，对发出存货进行计价的一种方法。采用这种方法，先购入的存货成本单位在后购入存货成本之前转出，据此确定发出存货和期末存货的成本。具体方法是：收入存货时，逐笔登记收入存货的数量、单价和金额；发出存货时，按照先进先出的原则逐笔登记存货的发出成本和结存金额。

先进先出法的优点是使企业不能随意挑选存货计价以调整当期利润，缺点是工作量比较繁琐，特别对于存货进出量频繁的企业更是如此。而且当物价上涨时，会高估企业当期利润和库存存货价值；反之，会低估企业存货价值和当期利润。

在通货膨胀情况下，先进先出法会虚增利润，增加企业的税收负担，不利于企业资本保全。而且，先进先出法对发出的材料要逐笔进行计价并登记明细账的发出与结存，核算手续比较繁琐。

为了更好的理解该词，以下是其英文释义：First In, First Out, commonly known as FIFO, is an asset-management and valuation method in which assets produced or acquired first are sold, used, or disposed of first. For tax purposes, FIFO assumes that assets with the oldest costs are included in the income statement's cost of goods sold (COGS). The remaining inventory assets are matched to the assets that are most recently purchased or produced.

双语例句：

（1）The FIFO method is used for cost flow assumption purposes. In manufacturing, as items progress to later development stages and as finished inventory items are sold, the associated costs with that product must be recognized as an expense. Under FIFO, it is assumed that the cost of inventory purchased first will be recognized first. The dollar value of total inventory decreases in this process because inventory has been removed from the company’s ownership. The costs associated with the inventory may be calculated in several ways — one being the FIFO method.

先进先出法用于成本流假设目的。在制造过程中，随着物料进入后期开发阶段以及出售成品库存物料，与该产品相关的成本必须确认为费用。在先进先出法下，假定首先确认的是存货成本。在此过程中，总库存的美元价值下降了，因为库存已从公司的所有权中删除。与库存相关的成本可以通过几种方法来计算——一种是先进先出法。

（2）The FIFO method follows the logic that to avoid obsolescence, a company would sell the oldest inventory items first and maintain the newest items in inventory. Although the actual inventory valuation method used does not need to follow the actual flow of inventory through a company, an entity must be able to support why it selected the use of a particular inventory valuation method.

先进先出法遵循这样的逻辑，即为避免过时，公司将首先出售最旧的库存物料并维护库存中的最新物料。尽管使用的实际库存评估方法不需要遵循通过公司的实际库存流向，但一个实体必须能够支持其选择使用特定库存评估方法的原因。