Assembly is the simplest symbolic languge there is....It's virtually impossile to work in binary so grouping the binary into a nmemonic helps remember the code....
example
Mov R0, #55H ; load R0 with 55H
Mov R1, #85H ; load R1 with 85H
how to access ram memory
Mov 00, #55H ; ram location 00 has 55H data
Mov 01 , #85H ; ram location 01 has 85H data
These two examples are the same... R0 and R1 are in position 0 and 1 in internal ram..