What is a type definition? When reading about data types, "type definition" is often used without any prior explanation to what it means.

For example, in https://en.wikipedia.org/wiki/Type_system, we have the sentence "...  since C++ has stronger rules regarding type definitions  ..."

Any help in clarifying what the difference between, for example, type and type definition is greatly appreciated!
"Defining" a type is the act of building a new type composed of one or more pre-existing data types. For example, the "Complex Number" type is often declared as an ordered pair of "Real Numbers" :

Type Complex
  Real a
  Real b
End


a and b being the real and imaginary parts.

This sample of pseudo-code is a "Type Definition".