Lvm works with physical volumes(pv), volume groups(vg) and logical volumes(lv). In short
you create a physical volume from a disk, then create a volume group and then you can create logical volumes from the the space available in the volume group. If you need more space in your volume group, you add another disk to your system, then create a physical volume of that disk, extend your volume group with the new physical volume and then you have more space.
fdisk is only used for creating partitions, normally you create a partition and on top of a partition you create a fileystem or you can use the partition with for an lvm setup after which you create the filesystem on the logical volume(s). Yes that's the best way to do it because that way you can extend your filesystems while your system is online without having mess around with resizing partings using fdisk or parted/gparted. Linux Logical Volume Manager (LVM) tutorial