Physical Ability is a measure of the characters strength, stamina, and general health. If you are involved in close combat or some other dangerous or strenuous work, it will be your physical abilities that determine your success. If you are wounded or come down with an illness, it is this same attribute which will affect your rate of recovery.
Mental faculties reflect the characters intelligence, initiative and ability to reason. Everything from Military strategy and investment decisions, to the success of an essay or book, to the outcome of parliamentary debates are dependent on you mental faculties.
Sprit defines willpower, courage and the ability to preserve in unpleasant situations. In addition to aiding in your attempts to achieve tasks that require a great deal of courage to succeed, Spirit may be used to provide to create sparkling party talk, flirt with the Dukes niece or to otherwise persuade another to come around to your way of thinking through an emotional appeal.
Status defines what level of society a character is born into. Changes in Status only come with major life changes and only a little unless something extraordinary happens. Someone may be knighted for gallantry, someone may be given a peerage sort of as a "lifetime achievement award," or a relative may die and leave one a title, but very few people are going to get promoted in status for any short-term achievement. Most people in Victorian society will live there entire lives without changing their status.
Rank is a measure of your accomplishment within your profession. Gains in rank will be primarily through your own efforts, and (depending on circumstances) you can do so relatively quickly within the framework of game time. And rank won't go away unless you do something really bad (and sometimes even then!) The effects of Rank are generally localized to your profession. Army people have no time for navy people; the military condescend to the church, and everyone thinks politicians are a bunch of whipped-up rabble-rousers.
Reputation can make or break a man. Actions during the game can lead to quick short-term gains (or losses!) in reputation. Reputation is used to increase your influence. But that over time these fade. Really severe losses or really heroic gains in reputation will have a lingering effect, but small gains or losses can be erased just by the passage of time.