in Arduino mega2560, serial, serial1... Serial3 use same register or buffer

Projects Interfacing w/ Software on the Computer
1

Hi I want to use:
1 RFID Board
1 GDM Board
1 Bluetooth board
Each on its own port USART.
If I receive data at the same time for 2 ports at the same time will be lost? are saved in your own register or buffer?. Each serial port has its own record or buffer?
Or Is There a library to use 2 serial ports at a time and that can receive data at a time?
Thanks

2

If I receive data at the same time for 2 ports at the same time will be lost?

Since nothing happens at exactly the same time, no.

Each serial port has its own record or buffer?

Yes.

Or Is There a library to use 2 serial ports at a time and that can receive data at a time?

Yes. It's called HardwareSerial. Serial, Serial1, Serial2, and Serial3 are all instances of that class.