SnobA snob, guilty of snobbery, is a person that adopts the world-view that other people are inherently inferior for any one of a variety of reasons including supposed intellect, wealth, education, ancestry, etc. A snob imitates the manners, adopts the world-view and affects the lifestyle of a social class of people to which he or she either belongs or aspires. That "right" is not necessarily a birth-right: a Pseudo-intellectual is a type of snob.
A snob is perceived by those being imitated as an "arriviste", perhaps nouveau riche or parvenu, and the elite group closes ranks to exclude such outsiders, often by developing elaborate social codes, symbolic status and recognizable marks of language. The snobs in response refine their behavior model (Norbert Elias 1983).
Characteristically, snobs look down on people who are part of groups that they regard as inferior or flaunt their wealth in order to make others feel inferior. Compare the points of view embodied in the informal and subjective categories of "highbrow" and its contrasted "lowbrow".
The Oxford English Dictionary finds the word snab in a 1781 document with the meaning of shoemaker with a Scottish origin. The connection between "snab", also spelled "snob", and its more familiar meaning arising in England fifty years later is not direct.
The usual and more familiar story, now discredited, is that "snob" was used as schoolboy slang at Eton College in the post-Waterloo generation, when many more sons of the rich manufacturers of the booming industrial revolution were joining the sons of the gentry. The "snobs" designated the group of boys who were not "nobs", the nobility, those who carried the designation "Hon." before their names if they did not actually carry a courtesy title. The "snobs" were those who, sine nobilitate—the former etymology ran— ("without a title to nobility"), carried themselves as "swells". By 1831, "nob" and "snob", whatever their current meaning at the time and their derivation, were clearly opposed social groups, for the Lincoln Herald (on 22 July, 1831) could declare "The snobs have lost their dirty seats - the honest nobs have got 'em." 
It is agreed, however, that the word "snob" broke into broad public usage with William Makepeace Thackeray's Book of Snobs, a collection of satiric sketches that appeared in the magazine Punch and were collected and published in 1848. Thackeray's definition of "snob" then: "He who meanly admires mean things is a Snob." The "mean things" were the showy things of this world, like a secretaryship in the Queen's Cabinet, where Prime Ministers invariably retired as earls.
"Suppose in a game of life— and it is but a twopenny game after all— you are equally eager of winning. Shall you be ashamed of your ambition, or glory in it?"
— Thackeray, "Autour de mon Chapeau," 1863
Thackeray had many opportunities to study snobs in action as he grew up. He was born in Calcutta, India, the only son of a Collector in the service of the British East India Company, a sphere of opportunity for Englishmen of talent whose social standing was an impediment to a career at home, but who in India could lord it like a "nabob". After his father died, Thackeray was sent home to England to be educated at the ancient and respectable though not quite stylish public school Charterhouse, and at Trinity College, Cambridge.
In a hierarchic organization, such as the British Raj, the Austro-Hungarian Empire, the Jesuits or the United States Air Force, the path to advancement from below is often eased for those who most whole-heartedly adopt the point-of-view of their superiors.
In a less hierarchic society, such as today's Western democracies, snobbism takes new forms, with a different dynamic. In modern society, certain celebrity figures occupy the center of an "in-group", and snobs imitate the outward style of those perceived as being at the center. This imitation is often characterized by conspicuous consumption, a phenomenon named and described by the economist and sociologist Thorstein Veblen, in The Theory of the Leisure Class (1899).