Both will return the absolute value of a number. The difference is that math.fabs(number) will always return a floating-point number even if the argument is an integer, whereas abs() will return a floating-point or an integer depending upon the argument. In case the argument is a complex number, abs() will return the magnitude part, whereas fabs() will return an error. To use the fabs() function we need to import the library “math” while the abs() function comes with the standard library of Python.

The abs() and fabs() functions are both used to compute the absolute value of a number, but they are implemented differently in different programming languages.

1. abs() function:
   • abs() is a built-in function in many programming languages, including Python.
   • It is used to compute the absolute value of an integer or a floating-point number.
   • In Python, the abs() function can be used with any numeric type (int, float, etc.) and returns a positive value.
   • Example usage in Python: abs(-5) returns 5, abs(3.14) returns 3.14.
2. fabs() function:
   • fabs() is a function defined in the C programming language’s standard library.
   • It is used specifically for computing the absolute value of a floating-point number.
   • fabs() is part of the math.h header file in C.
   • Unlike abs(), fabs() is designed to work with floating-point numbers only and returns a floating-point value.
   • Example usage in C: fabs(-3.14) returns 3.14.

In summary, abs() is a more generic function that works with both integers and floating-point numbers, whereas fabs() is specifically designed for computing the absolute value of floating-point numbers. The choice between abs() and fabs() depends on the programming language and the type of numbers you are working with.