Lexicon

The words in orange belong to the Vietnamese native lexical stock while the ones in green belong to the Sino-Vietnamese vocabulary.

Like other east Asian countries, as a result of close ties with China for thousands of years, much of the Vietnamese lexicon relating to science and politics is derived from Chinese - see Sino-Vietnamese vocabulary. 

At least 60% of the lexical stock has Chinese roots, not including naturalized word borrowings from China, although many compound words are composed of native Vietnamese words combined with Chinese borrowings. One can usually distinguish between a native Vietnamese word and a Chinese borrowing if it can be reduplicated or its meaning does not change when the tone is shifted. As a result of French occupation, Vietnamese has since had many words borrowed from the French language, for example cà phê (from French café). 

Nowadays, many new words are being added to the language's lexicon due to heavy Western cultural influence; these are usually borrowed from English, for example TV (though usually seen in the written form as tivi). Sometimes these borrowings are calques literally translated into Vietnamese (for example, software is calqued into phần mềm, which literally means "soft part").

~Info courtesy of Wikipedia~