JAQL stands for JSON Analytical Query Language, and it’s a JSON based syntax proprietary to Sisense which the Sisense UI uses to describe all the queries it runs - those that populate filter options and samples, and those that retrieve data for widgets.
A JAQL query describes which fields (“dimensions”) should be included, as well as what aggregations (“measures”) and filters should be applied to them. The Sisense Web Server translates these queries into ElastiCube’s own query language, and takes care of the required joins and internal operations, allowing you the ability to write queries without an in-depth knowledge of the underlying ElastiCube relational schema.
There is another language called JAQL, currently being developed by IBM, which shows up when Google-searching the term. These two languages serve a similar purpose, however they aren’t similar or related in any other way.
If you're new to JAQL, start by following our JAQL Tutorial.
Afterwards, you can find all the available aggregations, filters and options in the full JAQL Syntax Reference