A business analyst (BA) is someone who analyzes an organization or business domain (real or hypothetical) and documents its business or processes or systems, assessing the business model or its integration with technology. Business Analyst helps in guiding businesses in improving processes, products, services and software through data analysis.

A functional analyst is a type of business analyst who specializes in a specific technology, line of business, domain or industry. These functional analysts, owing to their expertise in a particular field are fully aware of the attributes, characteristics, and functions of their field
A systems analyst is a person who uses analysis and design techniques to solve business problems using information technology. Systems analysts may serve as change agents who identify the organizational improvements needed, design systems to implement those changes, and train and motivate others to use the systems.

If you want some additional information about related information systems jobs, check out the following

• Jobs for IS Majors – https://youtu.be/7v5g91c1SWI
• Business Analyst vs Project Manager – https://youtu.be/7UttoQ3qwxI