Understanding and Choosing Your Level or Argentine Tango Dancing :
Intro-Beginner:
You have only basic knowledge of Argentine Tango and are still learning how to apply the concepts of communication, connection, embrace, frame to your dance and learning how to walk, suspend and pivot with your partner. Your knowledge of Tango vocabulary is limited.
Beginner/Intermediate
At least one term of classes. You can navigate the dance floor, walk confidently in various positions, execute ochos and turns confidently. You still need to improve your technique and repertoire and concentrate on dancing to the music and on the connection with your partner. Your Argentine Tango vocabulary is expanding to include boleos, ganchos, barridas, and paradas.
Intermediate
At least 2 years experience of weekly classes and dancing or 1 year of classes and workshop and intensive practice. You are familiar with all the basic tango steps (walking, ochos, turns, barridas, boleos, sacadas, ganchos, molinete) and are starting to improvise your dance, concentrating on musicality and connection with your partner. You can understand steps by watching and then working them out with your partner, requiring only the finer details to be explained by the teacher.
Advanced
At least 3 years intensive classes, workshops and practice. You should be fluent and comfortable with all tango steps, and are concerned with developing your dancing through improvisation, musicality and connection with your partner, allowing the teachers to explore the possibilities of these relationships.
Bear in mind some teachers require you to know the basics of their particular style for intermediate and advanced levels. As a general rule, if you don't know a teacher, it is always worth going to the beginner/intermediate class to get used to their style and technique.
Tango does not have exams or tests to determine which level you should take. However if you are unsure, please ask whoever your regular teacher is to advise you on which class to take - too hard, and you will struggle, too easy and you will be bored. Also if the class involves changing partners it is better to be with people at a similar level to yourself.
Even if you are an experienced dancer, the more basic level workshops will remind you of basic technical tips and help correct bad habits, and refresh the fundamental style, technique and terminology used by the teachers.
Here is a link to a wonderful article that explains in more detail why it is important to master the basics before attempting intermediate/advanced level classes.