移民官员在抵达时真正在柜台做什么？

When you arrive to a country by airplane and you go through the border control, what the immigration officer really does behind the counter? In Asia, I assume they firstly check if your passport needs a visa or not, secondly they check your passport data and I have noticed they also scan it for record purposes and lastly they take a photo of you by asking you to look at their camera. What else would they do? Would there be a passport authenticity check by placing it under a specific machine or it's just the scanner? Would they check your data against a possible flight list? When you arrive to a country by airplane and yo