Data on a computer is usually divided into sets of 8 bits, called a byte (see Introduction to Number Systems). A byte can store 256 different values but to store larger numbers, a set of bytes must be grouped together. The term 'Endian' refers to how these bytes are grouped together.

• Little Endian - In little-endian systems (for example, Intel machines), bytes are stored with the least significant byte first. For example, the hex bytes '2f 75 05' actually represent the number 0x05752f (357679 in decimal). '2f' is the least significant byte and '05' is the most significant byte.

• Big Endian - In big-endian systems (for example, Motorola machines), bytes are stored with the most significant byte first. In the same example, the hex bytes '2f 75 05' would represent the number 0x2f7505 (3110149) in decimal.

Which endian is used to convert bytes to numbers is very important. Every file in 010 Editor has an endian setting (LIT will appear in the Status Bar in little-endian mode, and BIG will appear in big-endian mode). Most tools and the Inspector use this endian setting. To change the default endian used for files, use the 'View > Endian' menu. 010 Editor can be configured to automatically set the endian based on the file extension (see Working with Interfaces).