Improver: This is not a complete beginner level. You are familiar with basics (Swing out, Lindy turn, Lindy circle) and are eager to start widening your dance vocabulary. In this level there will be a lot of focus on technique and lead / follow.
Intermediate: You dance for around a year. You have some ideas how to lead / follow. You are expected to be in control over both eight counts and six counts. You should be able to mix the two different basic steps without a problem and being in control over how to lead or follow the differences between them both. You should be an active social dancer and starting to learn connection, musicality and improvisation.
Intermediate / Advanced: Your dance connects to the music more and more. You have a good variety of figures. You can lead / follow clearly and should be able to manage slow tempo as well as more up tempo. Your technique and basics should be at the level where you can use different rhythmical variations and improvise.
Advanced: You have no problem leading, following, making improvisation and dancing to really fast music. You cannot count how many moves you know. You have your definitive dance style that makes your dance different.