Confused with intents and current challenge

Hi, I have been trying to figure this out for a little while now but I can't seem to grasp my mind around intents and what they are used for. All of this is making me feel so dumb! Obviously I watched the tutorial but I need an explanation in a simpler form. Also I am struggling with the current challenge on intents:

"We've updated our LaunchActivity to include a fuel level(mFuelLevel) for the Spacecraft. This value needs to be passed to the FlightActivity. Add the code to pass this value along via Intent. Use the key "Fuel_Level".

Here is my code! Please help!!!!!!!

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_launch);

// mFuelLevel is set elsewhere.
// Code ommitted for brevity!

mLaunchButton = (Button)findViewById(R.id.launchButton);
mLaunchButton.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v, mFuelLevel) {
    // Add your code in here!
    Intent intent = new Intent(LaunchActivity.this, FlightActivity.class);
     intent.getStringExtra("Fuel_Level", FlightActivity);
    startActivity(intent);
  }
});

} }