Upload code to Arduino board
How it's done
Connect Arduino with your computer using USB.
Upload Code to Arduino.
Select "Tools"->"Board"->[Arduino board]. In our case it is Arduino Uno.
Then select "Tools"->"Serial port"->[Your serial port used for communication with Arduino]. In our case it is /dev/tty.usbmodem1411.
Click on "File"->"Upload" to upload code to Arduino.