How to memorize what the Big-endian is and what the Little-endian is?
(The decision to use that meaningless names only in favor of J. Swift talent was quite stupid in the first place.)
So, here's a "simple" rule:
Let's say that the "end" is the starting byte of the memory word (lowest address).
Then "Little" will mean the less-significant, i.e. little part of the number is located at that first byte end.
In contrary, "Big" will mean the most-significant, i.e. biggest part of the number is located at the end (the first byte).
How to memorize which architecture uses which notation?
The PC which costs a little is based on the x86 architecture which is Little-endian.
Workstations, like SPARC, SGI cost big money, and also they are Big-endian.