Termux runs on Android natively and tries to make it behave like a distro with the team packaging a lot of packages for it, they usually have to patch the packages to use termux s PREFIX which is /data/data/com.termux/files/usr instead of /usr

I don't know what the future holds as currently some limitatiation on new android versions breaks termux and so it currently has forced itself on an older SDK version which makes it ineligible for google play (there's an experimental version on google play but the team recommends the f-droid version for now)

Running traditional Linux distros can also be done inside Termux via what's called proot which is like a chroot without requiring root.