Simple Explanation of What A Business Analyst Does
What is the role of a Business Analyst?
 A Business Analyst works with the technology team and business team. Their main job is to understand the business from the customers and business subject matters.
A Messenger
Business Analyst responsibilities are to be a liaison between customers and the technology team. BA gather requirements from clients and subject matters experts and transform the needs into documents and diagrams for technology team. Business analyst understands the entire business and captures all the needs and process.

Skills needed to be a Business Analyst
Able to communicate the right information between clients, stakeholders, and technology team. The entire team depends on the business analyst to bridge the gap on information between technology and business domain. 
Business Analyst leads requirement sessions and gathers right information pertaining to the business. 
BA will interview clients and stakeholders and understand how things are from a users perspective and collect information using different methodologies.
A good business analyst can lead, organize and manage teams.  

Another Explanation of BA
A video presentation: by Angelo the BA