Et cetera, usually abbreviated to etc. (archaic abbreviations include &/c., &c., and &ca.) is Latin for "and the others." "Et" is "and"; "cetera" is literally "other things." It is often used to represent the logical continuation of some sort of series of descriptions.
We need a lot of fruit: apples, bananas, oranges, etc.
(An error would be using "and etc.," which is redundant—"and and the others".)
The abbreviated versions should always be followed by a full stop (period), and it is customary, even in British English, in which there is frequently no comma before and in lists, that etc. always be preceded by a comma. Thus:
A, B, C, etc.
A, B, C etc.
In lists of persons, et al. is used in place of etc. (an abbreviation of et alii, meaning "and others"). Less common is the use of et al. in lists of places (where it abbreviates et alibi, meaning "and elsewhere".)
A common misspelling of the abbreviation is "ect."; a common mispronunciation is "ex cetera."
Et cetera can also (but uncommonly) be written with an ampersand symbol, followed by a c, which stands for cetera. This is not because "&" is shorthand for "and", but because it is actually a literal corruption of et. This abbrieviation is most commonly used in notations for mathematics or qualifacations.