Explicit Variable in C#

I imagine that you're probably asking about explicitly-typed variables.

These are variables which are given an explicit type when they are declared like this:

string s = "Hello";

In contrast, an implicitly-typed variable is one whose type is inferred by the compiler. Such variables are always declared using the 'var' keyword:

var s = "Hello";

Here 's' is inferred to be a variable of type string because it is being assigned a string.

's' is still strongly typed. If you attempt to subsequently assign it an incompatible value then you will get a compiler error:

s = 3; // compiler error