Chainik (East Slavic: чайник, "teakettle", "teapot") is a term that implies both ignorance and a certain amount of willingness to learn (as well as a propensity to cause disaster), but does not necessarily imply as little experience or short exposure time as newbie and is not as derogatory as luser.
Both a novice user and someone using a computer system for a long time without any understanding of the internals can be referred to as chainiks.
[1] It is a widespread term in Russian hackish, often used in an English context by Russian-speaking hackers especially in Israel (e.g. "Our new colleague is a complete chainik").
Some suggest the term is derived from a Russian folk custom to make a gift of a hollow thing – e.g., a pitted pumpkin, a kettle, or a teapot – to unsuccessful matchmakers of an aspiring groom rejected by a bride.
Over time the term entered other usages for unlucky, inept, or newbie people.