The example is from a course, it's for comparing two objects in java:

public class Complex {

    ...

    public boolean equals (Object obj) {
        if (obj instanceof Complex) {    // if obj is "Complex" (complex number) 
            Complex c =  (Complex) obj   // No idea
            return (real == c.real) && (imag == c.imag); 
            // I'm guessing real means [this].real
        }
        return false;
    }
}

So, my question is: "what does this: Complex c = (Complex) obj actually mean" ?

Also I've worked with python and c++, java is new for me.