Linux can see the partition table, and see that there's a partition there. It can also detect what partition type it is though the partition table. It can then mount the partition either through it being set in fstab, or some other mechanism - usually you would use the mount command, or it would be mounted by some tool in the desktop environment, which also uses the mount command.
In general, filesystems that arn't part of the root hierarchy are mounted under /mnt or /media with some name, though like a regular partition, they also have a partition name. Most systems will use the volume name or some random name for the exact location - for example, a drive whose volume name is potato, would be mounted under /volume/potato.
In general linux should have no issue reading a cleanly dismounted NTFS drive, and you can force mount a uncleanly dismounted one manually (with
mount -f). It can also sometimes read a NTFS drive windows can't read.