I have pretty specific taste preferences when it comes to tobacco. There are a fairly large number of blends that I do not care for.
A commercial driver license is a license issued in accordance with Federal Regulations that allows an individual to operate a commercial vehicle. Federal regulations require that an applicant be 18 years or older to apply for a commercial driver license (CDL) and be issued a commercial instruction permit.
In other states it might be called a license or a certification. A credential is the permit your state issues after it confirms that you've met the necessary requirements. A credential is only issued to individuals who have met all the state's requirements.