Immersion refers to being in an environment in which you have constant contact with a language. This may be one's own native language or one that one wishes to learn. There are two types of immersion: natural immersion and artificial immersion. Natural immersion is simply being in an area or environment where a certain language is spoken. An artificial immersion environment is one that is created because the natural environment is not available or possible.
Means of immersion:
- native speakers;
- listening to radio;
- listening to audio books;
- watching movies and television shows;
- watching YouTube;
- reading books/comics/websites/etc;
- chatting online;
- listening to music
- whatever else you can think of.
Several language learning methods make heavy use of immersion. The most famous of these is AJATT.