Materials for protection and prevention of ElectroStatic Discharge (ESD) can be categorized into three distinct groups -- separated by their ranges of conductivity to electrical charges.

Anti-Static:

Resistivity generally between 10⁹ and 10¹²  ohms per square.

Initial electrostatic charges are suppressed.

May be surface resistive, surface-coated or filled throughout.

Static Dissipative (SD) :

Resistivity generally between 10⁶ and 10⁹  ohms per square.

Low or no initial charges -- prevents discharge to from human contact.

May be either surface-coated or filled throughout.

Conductive (CN) :

Resistivity generally between 10³ and 10⁶ ohms per square.

No initial charges, provides path for charge to bleed off.

Usually carbon-particle or carbon-fiber filled throughout.