What it solves

Consider this instruction, where we have to add the two numbers 1 and 2.

Assembly

mov edx, 1
mov eax, 2
add eax, edx

Hexadecimal

ba01000000b80200000001d0

More readable hexadecimal

0:  ba 01 00 00 00   mov edx,0x1
5:  b8 02 00 00 00   mov eax,0x2
a:  01 d0            add eax,edx

Binary code with a mistake. Happy debugging

000000000001001010000000000100110000000000100011000000000001001100000000010100101000001101100011

The purpose of an assembly language can easily be seen with the help of the above example. Assembly language with the help of its syntax makes it easier to code and not worry about trivial tasks such as opcodes, address calculations, etc. Mistakes if any can easily identified in assembly rather than in binary. Imagine finding such mistakes in a pool of just a numbers!