They are used interchangeably since all of them involve working with data to find actionable insights. But I like to differentiate them based on the type of the question you’re asking:
- What:
What are my sales number for this quarter?
What is the profit for this year to date?
What are my sales number over the past 6 months?
What did the sales look like same quarter last year?
…
All of these questions are used to report on facts and tools that help you build data models and reports can be classified as “Business Intelligence” tools.
- Why:
Why is my sales number higher for this quarter compared to last quarter?
Why are we seeing increase in sales over the past 6 months?
Why are we seeing decrease in profit over the past 6 months?
Why does the profit this quarter less compared to same quarter last year?
…
All of these questions try to figure why something happened? A data analyst typically takes a stab at this. He might use existing Business Intelligence platform to pull data and/or also merge other data sets. He/she then applies data analysis techniques on the data to answer the “why” question and help business user get to the actionable insight.
- What’s next:
What will be my sales forecast for next year?
What will be our profit next year for Scenario A, B & C?
Which customers will cancel/churn next quarter?
Which new customers will convert to a high-value customer?
…
All of these questions try to “predict” what will happen next (based on historical data/patterns). Sometimes, you don’t know the questions in the first place so there’s a lot of pro-active thinking going on and usually a “data scientist” are doing that. Sometimes you start with a high level business problem and form “hypothesis” to drive your analysis. All of these can be classified under “data science”.
Now, as you can see as we progressed from What -> Why -> What’s next, the level of sophistication needed to do the analysis also increased. So you need a combination of people, process and technology platform in an organization to go from having a Business Intelligence maturity all the way to achieving data science capabilities.
Here’s a related blog post that I wrote on this a while back: Business Analytics Continuum: – Insight Extractor – Blog
..And you can check out other stuff I write about here: Insight Extractor – Blog – Paras Doshi’s Blog on Analytics, Data Science & Business Intelligence.