What Does Big-Endian Mean?
Big-endian refers to the way that data is sequentially stored in computer memory. Just as in books or magazines, where the first word appears in the top-left-hand corner of each page, the data in a big-endian system is organized such that the most significant digits or bytes appear in the upper left corner of a memory page, while the least significant ones appear in the bottom right-hand corner. This is in contrast to little-endian systems, in which the least significant data is organized in the upper left corner, while the most important bytes appear bottom-right. Both systems refer to a computer systems' "endianness," or how bytes are arranged for that particular system.
Techopedia Explains Big-Endian
Although endianness is much less common now, big-endian architecture was typically used in mainframe computers, most particularly in IBM mainframes, while PCs used the little-endian convention instead. The endianness being used by a system can become quite troublesome because it can create incompatibility between systems, ensuring more work when trying to port different programs and applications. When sending data over a network, there is no assurance that it can be understood when it gets to the other end. The incompatibility becomes a hindrance because a receiver using a big-endian system will misinterpret data that comes from a sender using a little-endian system and vice versa.
However, this problem has been eliminated in modern computer systems by automatic conversions. In addition, using big-endian or little-endian systems only makes sense if you are breaking data into several small values. If you are using a 32-bit register or more, you can store everything and there is no need to consider endianness at all.