Real accepts any real number. The default format for the Real datatype is a numeric field.
Real
numeric
A plain Real field:
<cf_terrafield name="MyReal" datatype="real" />
A Real field with a range of values:
<cf_terrafield name="MyDecimal" datatype="real" caption="your decimal" min="0" max="1" />
The Real field with a spinedit format:
spinedit
<cf_terrafield name="Mass" datatype="real" format="spinedit" caption="Mass" min="0" step="0.5" size="4" />