The part of a two-part memory address that remains constant and provides a reference point from which the location of a byte of data can be calculated. A base address is accompanied by an offset value that is added to the base to determine the exact location(the absolute address)of the information. The concept is similar to a street address system. For example, "2010 main street " plus an offset(10from the beginning of the block ). Base address are known as segment address in IBM pcs and compatibles; Data in these computers is identified by its position as a relative offset the start of the segment.

　　保持恒定的两部分内存地址的一部分并提供一个基准点，从这里可以计算一个字节数据的位置。基址伴随着一个加到基上的偏移值来确定信息准确的位置（绝对地址）。这一概念与街道地址系统雷同。例如：“大街2010号”由基（大街2000街段）加上偏移值（从街段开始的10号）。在IBMPC和兼容机中的数据按其相对于由段开始的相对偏移位置被识别。