This article explains the new law in a straight-ahead, concise manner. Click the above link to read. The following is a brief excerpt:   

Gov. Gavin Newsom signed Assembly Bill 1482 on Tuesday, enacting rent control in California, when “no one thought this could be done.”

He signed the legislation—which is designed to guard tenants against the most “egregious” rent hikes—as part of a press conference and housing tour in Oakland.

Once the law is in effect on January 1, the state will begin to regulate how much Californians’ rent can increase every year, limiting it to 5 percent, plus the local rate of inflation. The rules, however, will vary for cities that already have rent control laws. The measure will expire in 2030 (unless lawmakers vote to extend it).

Newsom has said that with AB 1482, California will boast the “nation’s strongest statewide renter protections.” On Tuesday, he thanked dozens of activists for their tenacity in advocating for a slate of new policies designed to help renters in California, which has the second highest poverty rate in the nation and a growing homeless population.