A title is a word used before a person's name to indicate rank. For instance somebody called Michael who is a Duke is called Duke Michael. For the most part the title and rank have the same name (as with Duke above), however the title for a male knight is Sir. In the SCA knights of either gender are often called Sir.
A title or position can appear without the person's name (e.g the President, the Earl), and may be asssociated with a particular role or area (e.g. the US President, Financial Director, Earl of Cornwall). Contrast this with an honorific is something that is attached to the name but is not normally used elsewhere, e.g. Mr, Sir, Mrs, Dr, Master.