Where in the code or system is the variable var usually located?

In C#, the keyword var is used for implicitly declaring a variable's type based on the assigned value. A variable declared with var is always local and must be initialized immediately.

The var variable is in the scope where it is declared — usually inside a method or a block of code. It cannot be a class field or a global variable.

Example:

void Example() {
    var number = 10; // number is a local variable of type int
    var text = "hello"; // text is a local variable of type string
}

Thus, var is syntactic sugar for local variables with an explicit type determined by the compiler.