How long does the effect of laser hair removal last?

Maybe it's because it's summer, but I keep getting self-conscious about my underarms.

I once wore something with baggy sleeves, and while walking, I was surprised because the inside of my side profile was clearly visible in the glass.

I've heard that hair removal products are harsh, so...

I keep thinking about laser hair removal.

I am wondering if I have to do this every summer, or if it can be done for a few years.

I bet a lot of people get laser hair removal, right?

Won't laser hair removal hurt by any chance?

I really hate it when any procedure hurts.

But do laser hair removal methods differ depending on the body part? I'm asking just in case about my calves or underarms.

The skin around the armpits is probably a bit more delicate...

I wonder if it's different.