A fact can be checked and proven, such as a date or a number. 事实可以核实和证明，比如一个日期或数字。
An opinion is what someone thinks, and it can differ from person to person. 观点是某人的看法，因人而异。
Words like "should", "best", or "terrible" often signal an opinion. "应该""最好""糟糕"这类词往往标志着观点。