JSON is frequently used for data exchange formats including the web browser with a common format. When we are dealing formated text with databases then it is essential to process JSON text retrieved from other systems with specific format to SQL Server database tables as JSON text.
JSON is newest addition to SQL Server family, from 2016 version onwards (which is under CTP 3.2 as of now).
A logical information about JSON functions within SQL Server that will enable to analyze/query JSON data, transform to relational format and export results as JSON text. (Source: Microsoft)
To know more I would recommend to go through the blog series posted by Jovan Popovic (MSFT). See below: