I want to interface PIC16F84A with mobile phone. The aim of my project is to create a device that can control the relays using SMS. Here is some questions:

1) WHat is UART? Please somebody explain it briefly.
2) I read in the internet that PIC16F84A dont have built in UART so we must create this function using the software(programming) Can somebody teach me how to do this?

3) If send the sms to mobile phones, is it possible that PIC16F84A can read this sms?

Please help me, sorry if my question is too easy for you guys. Actually I'm a beginner in this field. Hope will learn a lot from you guys. Thanks

Regards,
Fakhzan