Google: origin “left wing” “right wing”
First hit: http://ask.yahoo.com/ask/20011217.html
Anyhow, it basically comes down to the seating arrangements of the 1789 French National Assembly.
The left-wing, right-wing duality is quite a tricky one. In popular usage, left-wing generally describes bigger government, while right-wing is smaller government. The left-wing is (in general) more concerned with social programs, whereas the right-wing is more laissez-faire, pick-yourself-up-by-the-bootstraps kind of mentality.
But that’s REALLY simplifying it. Ask 5 people for definitions and you’ll probably get 6 answers.
Of course, then where do you put libertarians in this scheme? By many, they’re thought of as right-wing, but many of their beliefs are quite left-wing as well. When I went to university, the prevailing political model was divided into four quadrants, rather than two.
Freedom vs Order
Freedom vs Equality
It played out like this:
Freedom, Equality : Liberal
Order, Freedom : Conservative
Freedom, Freedom: Libertarian
Order, Equality: Populism
Other four-quadrant models augment the left-right duality with a democratic-totalitarian scale.
The middle ground is generally called “middle-of-the-road.”
The normal left-right dynamic is weird, though, in different parts of the world. For example, here in Hungary, the ruling Fidesz party is generally considered right-wing, whereas the Socialists are considered left-wing. Sound good so far? However, the Socialist party has been accused of favoring big business and lower social spending, which is traditionally associated with the right, whereas Fidesz claims to be the small-business, social spending party. On the other hand, Fidesz has a nationalist bent to it, which is considered extreme right, usually.
So while the labels are useful to an extent, the nuances of any given nation’s politics may be contrary to what is normally expected of a left-wing or right-wing government.