What is endian?

Some articles on endian:

Little-endian - Examples of Storing The Value 0A0B0C0Dh in Memory - Middle-endian
... Numerous other orderings, generically called middle-endian or mixed-endian, are possible ... On the PDP-11 (16-bit little-endian) for example, the compiler stored 32-bit values with the 16-bit halves swapped from the expected little-endian order ... This ordering is known as PDP-endian ...
Little-endian - Optimization
... The little-endian system has the property that the same value can be read from memory at different lengths without using different addresses (even when alignment restrictions are imposed) ... Although this little-endian property is rarely used directly by high-level programmers, it is often employed by code optimizers as well as by assembly language ... most-significant portion instead of the complete representation a big-endian processor may read such an approximation using the same base-address that would be used for the full value ...
SuperH
... The SH-3 and SH-4 architectures support both big-endian and little-endian byte ordering (they are bi-endian) ...
Little-endian - History
... Until 1970s virtually all processors were big-endian ... logic and byte level computations led to little-endian approach ... alludes to the issue that a value represented by the byte-string "UNIX" on a big-endian system may be stored as "NUXI" on a PDP-11 middle-endian system UNIX was one of ...
PowerPC - Design Features - Endian Modes
... that functions as a TLB with off-chip storage) are always done in big-endian mode ... The processor starts in big-endian mode ... In little-endian mode, the three lowest-order bits of the effective address are exclusive-ORed with a three bit value selected by the length of the ...