Wikipedia’s article on Magisterium has a neatly organized table listing the possible ways authoritative teaching is expressed in the Catholic Church, and showing what type of assent is required in each case. Infallible teaching is to be believed with an act of the virtue of faith; authoritative non-infallible teaching is to be accepted with “religious assent”.
Keep this summary handy for when people ask you whether a particular document’s teaching is infallible.