LVM Partitions are equals to OS partitions?
 

When we install a linux OS, we've an option to create partitions. In my laptop I've create partition for /opt, /home, / and /tmp.

Are these partitions the same type of partitions as the partitions created by LVM?

Not exactly.

LVM lives on top of disks or partitions whereas partitions are divisions of the disk itself.

However, functionally for creating filesystems you can think of a Logical Volume (LV) as a "logical partition".

To me LVM is superior to using partitions for most purposes:
1) There is a small limit to the number of partitions you can create on a single disk. The same disks under LVM can have many more LVs.
2) If you want to resize or remove a partition you have to resize all the partitions above it or recreate them. With LVM you can add or remove LVs as necessary and can resize them without worrying about what is on other LVs. (Both partitions and LVs are of course limited to how much space is physically available.)
3) With LVM you can combine partitions or disks into a much larger Volume Group (VG) so it appears as if it were a much larger "logical" disk. On systems with multiple disks this gives you even more LVs you can subdivide out of the VG or allows you to make an LV that is so large it spans multiple disks.