The Heckscher-Ohlin model is an economic theory that explains how countries trade based on their resources. It suggests that nations will export goods that use their abundant factors of production, like labor or capital, and import goods that require resources they lack. For example, a country rich in labor may export textiles while importing machinery. This model emphasizes the importance of factor endowments, which are the resources available in a country. By focusing on these endowments, the Heckscher-Ohlin model helps to predict trade patterns and the benefits of international trade, leading to more efficient global resource allocation.