Hey @thomas! Let me try to clarify:
InfluxQL is the original query language for InfluxDB. As the name suggests, it’s very similar to SQL. It works in the 1.x line.
Tick script is the scripting language we created early on to handle alerts and data processing (generally used with Kapacitor), which also works with 1.x.
Flux is a functional language that works in 1.6 and later as well as 2.0. It works for querying the database and writing custom logic. It’s meant to combine the features of InfluxQL and Flux into an easier language that’s capable of more data manipulation.