What Is an OBD-II Scanner?

What Is an OBD-II Scanner?
Onboard Diagnostics II (OBD-II) is a standardized system that the onboard computers in cars and trucks use for self-diagnostics and reporting. This system grew out of Californa Air Resources Board (CARB) regulations, and it was implemented with specifications that were developed by the Society of Automotive Engineers (SAE). Unlike earlier, OEM-specific OBD-I systems, OBD-II systems use the same communication protocols, code designations, and connectors from one manufacturer to another. OBD-II scanners are designed to provide access to the data that these systems are capable of providing.
Types of OBD-II Scanners
There are two basic categories of OBD-II scanners:
Code readers
Scan Tools
OBD-II code readers are typically inexpensive, no-frills devices that can read and clear codes from any vehicle that is equipped with OBD-II.