The abbreviation "etc." stands for "et cetera," which is a Latin term meaning "and other things" or "and so on." It is used to denote that there are additional items or examples that can be included in a list without having to write them all out. It's commonly used when the list is too long or when it's clear what the omitted items might be.
The term "et cetera" comes from Latin, where "et" means "and" and "cetera" means "the rest." It has been adopted into English and used as an abbreviation since the 17th century.