From Portable Network Graphics (PNG) Specification (Second Edition) ( 2003-11-10) byte order in which the most significant byte comes first, then the less significant bytes in descending order of significance ( MSB LSB for two-byte integers, MSB B2 B1 LSB for four-byte integers).

The Internet standard byte order (big-endian).

The order of bytes in a binary representation of a number as transmitted on the Internet. The most significant byte is first; for example, a 16-bit word representation of "256" would be 0x0100.