New Concept: Code-switching

Was listening to the c'est la vie radio show on cbc today and they mentioned the term code-switching. Apparently we are a hotbed of it/for it.

Code-switching is a linguistics term denoting the concurrent use of more than one language, or language variety, in conversation. Multilinguals - people who speak more than one language - sometimes use elements of multiple languages in conversing with each other. Thus, code-switching is the syntactically and phonologically appropriate use of more than one linguistic variety.
Code-switching is distinct from other language contact phenomena, such as borrowing, pidgins and creoles, loan translation (calques), and language transfer (language interference). Speakers form and establish a pidgin language when two or more speakers who do not speak a common language form an intermediate, third language. On the other hand, speakers practice code-switching when they are each fluent in both languages. Code mixing is a thematically related term, but the usage of the terms code-switching and code-mixing varies. Some scholars use either term to denote the same practice, while others apply code-mixing to denote the formal linguistic properties of said language-contact phenomena, and code-switching to denote the actual, spoken usages by multilingual persons
From Wikipedia