Can you explain what is meant by explicit data type definition in programming?

Explicit data type definition is when a programmer explicitly specifies the type of a variable or value in the code. In statically typed languages, such as Java or C++, you need to write the type before the variable name:

int age = 25;

In Python, which is dynamically typed, the type is usually not explicitly specified, but starting from Python 3.5, type annotations can be used to explicitly indicate the type:

def greet(name: str) -> str:
    return 'Hello, ' + name

Explicit type definition helps improve code readability, facilitates debugging, and allows static analysis tools to find errors before program execution.