I'm moving to a Macbook after long time on a desktop. I found a good bargain on a basic M1 MB Air, which is powerful enough for me but it is 256gb SSD, which is definitely enough for the useful things I need but is bit tight for my 110gb iTunes library and 60gb photo library. I could even stretch everything on the MB but that's all stuff I need seldomly on laptop so I rather to keep the MB light.
I thought to buy an external drive to hold all these stuff and just plug it in when I need it but I'm concerned about one thing: what happen if I sync my iPhone with iTunes (ye, I know it is Music now!) while the ext drive is not plugged in (I set "iTunes" to keep my library synced with the iPhone)? Does it removes all the music from the phone and re-upload it everytime I sync it with the drive plugged?