What each term actually means
A free CRM
A free CRM is a permanently free tier of a commercial product, not a trial that expires. The vendor gives away the core object model — contacts, deals, tasks, a pipeline — and funds it on the expectation that some users eventually outgrow the limits. Free tiers are usually complete enough to run real work.
A paid CRM
A paid CRM is the same product with the gates removed, plus the features that cost the vendor money to operate: telephony, messaging, storage and support. That explains most pricing logic. Anything with a marginal cost per use sits behind a paid plan; anything with near-zero marginal cost tends to be free.
