A multilingual person is someone who can communicate in more than one language actively (through speaking, writing, or signing). Multilingual people can speak any language they write in, but cannot necessarily write in any language they speak. More specifically, bilingual and trilingual people are those in comparable situations involving two or three languages, respectively. A multilingual person is generally referred to as a polyglot, a term that may also refer to people who learn multiple languages as a hobby.

Source: Wikipedia