Question about serial pins

Why is there only 1 seri in/out pins on the uno but with mega you have an extra 2 or 3. Is it software related or hardware related?

Hardware. The UART (Universal Asynchronous Receiver Transmitter) hardware includes shift registers and timing circuits. There is one set in the ATmega328P and four sets in the ATmega1280/2560.

You can "add" extra serial pins on Uno by using SoftwareSerial.

How would u send data instead of strings?

'U' would use Serial.write() instead of Serial.print().

I've never understood the point of writing an almost complete sentence in full, and just dropping the two characters from the word 'you'.

I am sorry I wass using my phone for the last post. I know how to use Serial.Write but my question was concerning software serial, and not the built in serial port. Do they have the same methods?