Little Endian & Big Endian are examples of Endianness.
Endianness differ from machine to machine with different architectures.
Say for example you have a number 250 , where we have 2 in hundreds place and 0 in ones place,
In case of machines following Big Endian number 250 which has 2 in hundreds place is stored in a memory location with smallest address.
At the same time in case of Little Endian , same number 250 , "2" is saved in memory location with highest memory !
We can find endianness of machine using a C program.
Hope you are clear about what endian is all about