What Is Vocabulary?
The noun vocabulary (or "vocab" for short) refers to the words used in a language.
"Vocabulary" can have at least three different meanings:
When learning a foreign language, our individual vocabulary in that language is one of the most important micro-skills to develop. Of course, all micro-skills like grammar, vocabulary and pronunciation are important. But it is far more difficult to communicate with no vocabulary than with no grammar. :-)
Active And Passive Vocabulary
In our own individual vocabulary, there is a difference between:
This is true for native speakers as well as for learners. In your own language, there are many words that you use regularly when speaking or writing. These words are part of your active vocabulary. And then there are many words that you understand when you hear them, on television for example, but do not use in everyday speech. These words are part of your passive vocabulary.