据悉 is an adverbial phrase meaning 'it is learned' or 'according to information received.' It conveys that the following statement is based on reports, rumors, or unofficial sources—not firsthand knowledge or confirmed facts. The character 据 means 'according to' or 'based on,' while 悉 means 'to know' or 'to be informed'; together, they form a formal, written expression of secondhand information.

This phrase is common in news reports, official announcements, and formal writing, but rarely used in casual speech. It carries a neutral-to-slightly-distant tone, suggesting reliability without claiming certainty. Unlike spoken alternatives like 听说 (tīng shuō), 据悉 implies the information comes from credible channels—though still unverified—and often introduces factual claims about events, policies, or developments.