Of course, you don't have a device called a mySerial connected to the pins, so why the instance is called mySerial is a mystery. A name like phone or cell would make a lot more sense.
No special reason,anything can be used.
Using mySerial.available() and mySerial.read()
mySerial.read() returns int type and i got series of special character(box like)when tried to display it using serial monitor.