BQL is a new, more powerful API based on normalized, curated, point-in-time data that allows you to perform aggregation, screening, calculations, and other analysis on Bloomberg's servers.
Benefits of BQL
Customizable: Go beyond the terminal's built-in functions and build your own custom outputs.
Fast: Reduces the number and complexity of steps compared to the old Bloomberg API.
Reduces data usage: Performing analysis and calculations in the cloud means you only download the data you need (as opposed to all the raw data necessary for an analysis), making it much less likely that you will hit the daily and monthly Bloomberg data download limits.
No programming required: Leverage what you know of Excel--no need to learn R or another programming language / software environment.
How do I get started with BQL?
BQLX: Support documentation. In addition to an Excel Formula References (formulas for the two query methods, cell referencing, display parameters, helper formulas), Bloomberg supplies "Getting Started" guides - including video tutorials, spreadsheets, and cheat sheets - for equities, funds, fixed income, economics, and portfolios.
NI FFM BQL: Bloomberg "Functions for the Market" case studies featuring the practical application of BQL.
"BQL Builder": Found in the Excel ribbon (includes sample queries).
Bloomberg for Education videos: 5-part series for how to effectively use BQL.