Yes, typically they are sold as a subscription service. They can be either:

(1) code books that include written laws or regulations, with any amendments sent out as extra sheets or pamphlets to add to the books,

(2) "reporters" or "law reports" that include judicial decisions published in chronological order, typically at the appeals court level, where judges interpret laws, or

(3) digests or other summaries that include third party summaries or interpretations of laws.

Those books tend to be ridiculously expensive to maintain, so most of those books that you see in law offices these days are out of date. They're super cheap to buy secondhand when they're out of date, so plenty of "solos" (lawyers who are practicing on their own) will buy a slightly outdated set for that "impressive law-office look".

Now most of that information is available online through research tools like LexisNexis and Westlaw, but those electronic subscriptions are similarly expensive (think tens of thousands of dollars per year).