I think of type as a range of values that the variable can take whereas the rest is known constant or does not matter. Variables (instances or objects), which share common properties, are considered to belong to the same type/kind/class. That is, the type properties are constant across the type. The type is actually a common property of a class of objects (variables). The variables have a variable part, which may change, making them flipping from one subtype to the other. However, the same applies to subtypes: subtypes also share a common constant property.
I may describe a class by a circle in Vienn Diagramm. Its subspheres would be types or variables. I think that the variable means that it has some fixed part, its type, and variable part, which make it variable and not constant. The constants or values would be an elementary point in the diagramm.
For instance, integer is a subtype of real. Integer variable means that it can take concrete values within the range of the integer area. Similarly, boolean variables, taking only values 0 and 1, are subtype of integer. But, what is a constant 1? Is it a real or integer or boolean variable or it is a specific type, instances of which have a common property: they have a value of 1? Is it a known treatment?
My interest stems from the practice: how can I save memory fixing the common part of variables in a language processing framework?