Effective cover is the distance measured from the face of the member to the center of area ( centroid ) of reinforcement, i.e., tension or compression reinforcement.
Effective cover = overall depth – effective depth
Effective cover = clear cover + (diameter of bar/2)
Clear cover is the distance measured from the exposed concrete surface (Without plaster and other finishes) to the nearest surface of the reinforcing bar.
According to IS 456 (Clause 26.4.1) Nominal cover (concrete cover or clear cover) can be defined as “is the design depth of concrete cover to all steel reinforcements, including links”.
This is the same thing as clear cover albeit with a different name.