Difference between SHL and SAL in 80x86

Question

I have learned how to work with 80x86 assembler, so in bit-wise shift operation, I faced a problem with SAL and SHL usage. I means the difference between lines of code as fo

Answer 1

shl and sal are the same.They have same machine code.
shr and sar are NOT the same.They have almost same machine code.(but not)
Check this.