What Is Difference Between Data Rate And Signal Rate?

One goal in telecommunications is to increase the date rate while decreasing the signal rate.
Increasing the data rate increases the speed of transmission, while Decreasing the signal rate decreases the bend width requirement.
The relationship between data rate and signal rate can represented by
   S= CN1/r baud
where N= data rate(bps)
C= case factor(worst, best, average, worst- when need for maximum signal rate,  Best- when we need minimum, but we are interested in average)
S= No, lf signal elements
r= ratio betwiin data and signal element

A data element is the smallest entity that can represent a piece of information: This is the bit.
A signal element is the shortest unit (time wise) of a digital signal

One goal in telecommunications is to increase the date rate while decreasing the signal rate.Increasing the data rate increases the speed of transmission, while Decreasing the signal rate decreases the bend width requirement. 

Signal is small while data is is meaningful.