The title company has researched the title. This is called a “preliminary title report”, “Prelim” or “P.R.”
Based on their research and any conditions or that need to be satisfied or exemptions, they agree to insure the title through a policy of title insurance.
A Title Commitment is issued by a title insurer or their agent. This “commits” or requires the title company to issue a title policy as long as the requirements set forth on the commitment are met and the closing and issuance of the policy meets all the title company’s standard procedures. Generally, a title commitment is issued directly prior to the closing for the buyer (or lender in the case of a mortgagee policy) or their attorney to review. After the closing then a title policy is issued.
The idea is similar to a loan commitment affecting a new mortgage.