Conversion from decimal to bianary

This a program for conversion from decimal to binary where I have some problem to understand the binary function---

Code:

#include <iostream>

using namespace std;

void binary(int);

int main(void) {

int number;

cout << "Please enter a positive integer: ";

cin >> number;

if (number < 0)

cout << "That is not a positive integer.\n";

else {

cout << number << " converted to binary is: ";

binary(number);

cout << endl;

}

}

void binary(int number) {

int remainder;

if(number <= 1) {

cout << number;

return;

}

remainder = number%2;

binary(number >> 1);

cout << remainder;

}

Say, I would like to convert Decimal 11 to binary number. The program is running properly and giving the answer 1011. I guess that the binary function will be started with 11 and goes to

remainder = number%2;

The reminder will be 1 but the number is still 11 , right ? I did not understand the function here : binary(number >> 1) due to the ">>" sign.

Anyone explain it for me a little ?