Seeking a simple ATmega32 program PB port output 0X55, 0Xaa

[Tarsha]

I just came into contact with the [ATMEGA32 AVR microcontroller]( link url) but didn't understand how to control the output of the I/O port.
Are the I/O control method of AVR's single-chip microcomputer and 51 different? Or is this MCU different? For example, what do PORTA and DDRA stand for because I didn't seem to see any more detailed explanations in the book?
Can you explain what the I/O output process of this single-chip microcomputer is like?
Many thanks for the help!
https://www.utmel.com/components/atmega32-avr-microcontroller-pins-datasheet-and-using-atmega32-with-arduino-ide-video?id=969

[crispyoz]

@Tarsha This forum is for discussion of the Onion Omega2 product range, try posting your question in the arduino forum forum.arduino.cc