Difference between capture and passing an argument in lambda functions

I understand the lambda function and the purpose of it in c++ 11. But i do not understand the difference between "Capturing the value" and "Passing an argument". For Instance..

#include <iostream>
#include <functional>
using namespace std;

int add(int a,int b){
    return a+b;
}

int main(int argc, char** argv){

    function <int(int,int)> cppstyle;
    cppstyle = add;

    auto l = [] (function <int(int,int)> f,int a, int b) {return f(a,b);};

    cout << l(cppstyle,10,30) <<"\n";   
}

The output of above code is same as below code..

#include <iostream>
#include <functional>
using namespace std;

int add(int a,int b){
    return a+b;
}

int main(int argc, char** argv){

    function <int(int,int)> cppstyle;
    cppstyle = add;

    auto l = [cppstyle] (int a, int b) {return cppstyle(a,b);};

    cout << l(10,30) <<"\n";    
}

Is capturing a value is similar as passing the value as an argument? or capture has some special meaning?