The least significant bit (LSB) is the lowest bit in a series of numbers. That is, if you represent a series of values in binary, the least significant bit would be the rightmost bit or the number on the far right.
The LSB is also known as the “rightmost” or “past-the-end” bit. If the LSB is on the right, the architecture is called “little-endian.” For example, in a little-endian architecture, the LSB of binary number 00000001 is 1.
LSB is a term that has significance in digital systems. It is used to describe values at the lowest end of a binary number.
These values are often located in the leftmost or rightmost bit(s) of registers and memory. The concept is one way of referring to the least significant unit.
A significant bit is an important or meaningful bit of data. When the least significant bit is discussed, it is typically in association with computer architecture and data storage.
The least significant bit generally refers to the lowest ordered bit in a binary number. In a hexadecimal (base 16) numbering system, it would be the rightmost bit (for example, 0b or 0x80).
Binary Numbers
As you probably realize, computers operate on binary numbers. Each digit in a number is either 1 or 0. In a series of 8 bits in binary format, the leftmost (least significant) bit has a value of 1 and all the other bits have a value of 0.
This makes the LSB the most powerful bit because it represents all the other bits that follow it. To illustrate this, try to reach into your pocket and pull out only your wallet.
The wallet will fall out eventually if you keep pulling, but it’s like trying to pull only one coin out of a slot machine.
You will likely have to go through many other things that collectively make up your pocket before you find just one item within it.
