Every online product publishes two documents in its footer: a Privacy Policy and a Terms of Service (sometimes called Terms & Conditions or Terms of Use). They look similar, they're written by the same lawyers, and most people lump them together. They are not the same thing.
The one-line difference
A Privacy Policy describes what the company does with your data. A Terms of Service describes the rules of using the product — your obligations, the company's obligations, what happens if either side breaks them.
Side-by-side
What it covers
Privacy Policy: data collection, processing, sharing, retention, user rights, security practices, international transfers.
Terms of Service: account rules, acceptable use, payment terms, intellectual property, warranties (or the absence of them), liability caps, indemnification, dispute resolution and governing law.
Who it protects
Privacy Policy: it's a disclosure obligation under privacy law — it primarily protects the user by forcing the company to be transparent.
Terms of Service: it's a contract that primarily protects the company by setting the rules of engagement and limiting their exposure.
Legal basis
Privacy Policy: required by privacy regulations (GDPR, CCPA, LGPD, etc.).
Terms of Service: standard contract law. Not strictly mandated, but practically unavoidable for any online product.
How they change
Both documents are updated frequently — but for different reasons. Privacy Policies move when data practices change. Terms of Service move when business models, pricing, or risk posture change.
Why this matters for users
When a company changes its Privacy Policy, the question is "what do they now do with my data that they didn't do yesterday?" When a company changes its Terms of Service, the question is "what can I now no longer do — or sue them for — that I could yesterday?" Different stakes, different reading lens.