(N/A) $\Rightarrow$ Segmentation: It is the division of an animal's body into a series of repetitive segments.
$\Rightarrow$ True Segmentation (Metamerism): It is observed in phyla $Annelida$,$Arthropoda$,and $Chordata$. In this,the body is divided into repetitive segments called metameres,where both external and internal organs are repeated. For example,in earthworms $(Pheretima)$,the body shows clear external and internal metamerism.
$\Rightarrow$ False Segmentation (Pseudometamerism): It occurs when the body is divided into many segments,but each segment is independent and not derived from the same embryonic origin. Each segment (proglottid) is capable of performing biological functions like reproduction. The growth of the body occurs by adding new segments from the anterior side (neck region). For example,in tapeworms ($Taenia$ $solium$).