All states except Michigan and Wisconsin currently share information about traffic tickets. Soon, that membership may climb to include all 50 U.S. states, Canada and Mexico. An out-of-state conviction also affects the points on your drivers' license. In California, most out-of-state moving violations are translated to one-point offenses; reckless driving, DUI and similar offenses are two-point violations.
Drivers' License Compact
45 states share all information about traffic tickets through the DLC. If you receive a ticket in a member state, all other member states learn about it. Georgia, Massachusetts, Michigan, Tennessee and Wisconsin are the only non-members, although some of these states have informal arrangements regarding information-sharing.
Non-Resident Violator Compact
The 44-state NRVC works a bit differently. Member states only share information about outstanding traffic tickets. So, if you receive a ticket in Nevada but fail to pay the fine or otherwise appear in court, that Nevada arrest warrant may follow you to another state.
California does not belong to the NRVC, and neither does Alaska, Michigan, Montana, Oregon nor Wisconsin. But don't count on an out-of-state warrant being a secret in a non-member state. That information may be shared informally or through the more comprehensive DLC.
National Driver Register
All 50 states and the District of Columbia belong to the NDR, which publishes a list of all drivers who have had their licenses suspended or revoked. If you try to apply for a drivers' license in California but have a suspended license or DUI conviction in Arizona, the California DMV will probably not issue a license until you are off the high-risk-driver list.
The Drivers' License Agreement may one day replace both the DLC and NRVC with a one-driver, one-record system; the DLA would also include Mexican and Canadian provinces. But, to date, only Arkansas, Connecticut and Massachusetts are DLA states.