Kamal
A Ph.D. is “given” when a thesis is successfully defended, which is the first and most crucial distinction (plus additional duties depending on the department). A PostDoc, on the other hand, is a non-defendable temporary employment assignment from a university or other organization.
In comparison to a Ph.D. student, a postdoctoral researcher has more discretion over the direction of their research. Postdocs are usually needed to get financing (as lead principal investigators or collaborators) and teach courses in addition to completing research objectives and reporting results.
