A MILLER was essential for grinding flour from grain, a WAINWRIGHT was a wagon builder, and BISHOP was in the employ of a Bishop. Different surnames often developed from the same occupation based on the language of the country of origin (MÜLLER, for example, is German for Miller).
Examples: ALDERMAN, an official clerk of the court; TAYLOR, one that makes or repairs garments; CARTER, a maker/driver of carts; OUTLAW, an outlaw or criminal
Despite these basic surname classifications, many last names or surnames of today seem to defy explanation. The majority of these are probably corruptions of the original surnames -- variations that have become disguised almost beyond recognition.
Surname spelling and pronunciation has evolved over many centuries, often making it hard for current generations to determine the origin and evolution of their surnames.
Such family name derivations, resulting from a variety of factors, tend to confound both genealogists and etymologists.
It is fairly common for different branches of the same family to carry different last names, as the majority of English and American surnames have, in their history, appeared in four to more than a dozen variant spellings. Therefore, when researching the origin of your surname, it is important to work your way back through the generations in order to determine the original family name, as the surname that you carry now may have an entirely different meaning than the surname of your distant ancestor.
It is also important to remember that some surnames, though their origins may appear obvious, aren't what they seem. BANKER, for example, is not an occupational surname, instead meaning "dweller on a hillside."
By Kimberly Powell, About.com Guide