So what does this really mean?

Assuming a base or radix of 10, I will attempt to explain it using an example.

Consider the following value:

623.57185

I can represent this value in any of the following ways (where * indicates multiplication):

.62357185*1000
6.2357185*100
62.357185*10
623.57185*1
6235.7185*0.1
62357.185*0.01
623571.85*0.001
6235718.5*0.0001
62357185.*0.00001

In other words, I can represent the value as a mantissa (62357185) multiplied by a factor where the purpose of the factor is to represent a left or right shift in the position of the decimal point.