arrangement vs alignment What's the difference in their English meaning? It's so confusing..

this video has a good explanation:

I watched it already. But have a problem for memorizing it because the meanings sound the same. So, I was curious if they have different meaning in the usage in real life or something.

Alignment refers to the placement bias of a single item (e.g. horizontal start/center/end, vertical top/center/bottom). this is well-established usage throughout Android, iOS, HTML/CSS, etc.