Differentiate Primary succession and Secondary succession.

Explanation

`{:("Primary succession","Secondary succession"),("Devoloping in an barren area.","Developing in disturbed area."),("Initiated dues to biological or any other","Starts dues to ecternal factors only."),("external factors",""),("No soil, while primary succession starts","It starts where soil covers is already present."),("Pioneer species come from outside","Pioneer species develop from existing"),("environment.","environment."),("It makes more time to complete.","It takes comparatively less time to complete."):}`