The major difference is for becoming a data analyst, you need to have better technical skills than a BI analyst. Both BI analysts and data analysts work together in an organization. If a company get a project, BI analyst has to find out the requirements and send them to a data analyst.
A data analyst has to understand the data and make statistical inferences from data. Also, a data analyst has to make visualizations and bring out useful insights.
BI analyst has to present these inferences to stakeholders. So, BI analysts should have good presentation and communication skills.
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You can know more about data analyst and business analyst roles in a company from this video: