Depending on context
, either the most signifigant byte
or most signifigant bit
. For example, in a 32-bit word
, the MSBit is equal to 1<<31 == 2^31 == 2147483748
, whereas the MSByte is equal to i<<24 == i*(1<<24) == i*16777216, where i is the value of the byte; for example, if i==1, MSByte==16777216
Contrast this to the LSB, which is always equivalent to 1 (whether it's the LSBit or LSByte).
Both of these definitions are assuming 2's complement and/or unsigned integer values. The meanings change signifigantly (no pun intended) when applied to 1's complement or signed magnitude or fixed point or whatever.