MOST SIGNIFICANT BIT AND LEFT SIGNIFICANT BIT

 MSB stands for most significant bit, while LSB is least significant bit. In binary terms, the MSB is the bit that has the greatest effect on the number, and it is the left-most bit. For example, for a binary number 0011 0101, the Most Significant 4 bits would be 0011. The Least Significant 4 bits would be 0101.