Data Connectivity Technologies and Functions:SQL: Structured Query Language used for managing and manipulating relational databases.XML and JSON: Markup languages for data interchange; XML is more verbose, while JSON is more lightweight and often used with web APIs.Comparing XML and JSON:XML is a markup language much like HTML$.($W$3$Schools$)$JSON is independent of any programming language and is a common API output in a wide variety of applications. $($Amazon$)$Data Connectivity Tools and Technologies:OLEDB: Object Linking and Embedding Database, used for accessing data from various database management systems.ODBC: Open Database Connectivity, a standard API for accessing database management systems.JDBC: Java Database Connectivity, an API for connecting Java applications to a database.ADO and ADO.NET: ActiveX Data Object and its $.$NET version, used for accessing data in a unified way in Microsoft environments.Purpose and Similarities:All these technologies provide a means for application to connect and interact with databases.They can be grouped under "Database Connectivity APIs since they serve a common purpose of database interaction.