The job of Air Traffic Services (ICAO Annex 11) is to prevent collisions, expedite traffic, and provide information and alerting, but ATS does not relieve the pilot of their own collision-avoidance responsibility under the Rules of the Air.
ATC issues clearances and instructions you must comply with, and provides separation according to airspace class. A Flight Information Service (FIS) is information only, it may never instruct an aircraft in the air. The callsign suffix tells you who you've got: "Information" is a FIS (a FISO), "Radio" is an Air/Ground Communication Service (AGCS), and a named ATC unit ("Tower", "Approach", "Radar") is control.