A business analyst works to understand human systems and recommend ways they can improve. business analysis is the verb meaning the same. This means that business analysis is misnamed as anyone can perform business analysis on just about any process, whether or not that process takes place in a business domain.
[!quote] Business analysis involves understanding how organisations function to accomplish their purposes, and defining the capabilities an organisation requires to provide products and services to external stakeholders. ^[A Guide to the Business Analysis Body of Knowledge® (BABOK ( PDFDrive ).pdf]
The above definition which comes from the BABoK 2.0 is a relatively structured definition. Ultimately any attempt to break down, understand, or improve any aspect of human systems will inevitably use business analysis.
Business analysis is most often used to assist in the effective delivery of Technologies in a business environment. In its early use business analysis was a very specific activity use in IT delivery however business analysis has evolved over time and now is a very generalist practice.
As such business analysis has a ton of overlap and scoped implementation which can make the discussion of BA confusing or in-nuanced.