ASP.NET is a technology developed by Microsoft, one of the largest companies in the software market. This technology allows programmers to build Websites, Web application and Mobile application. It also gives the facility to a developer to write code in multiple supported languages like VB.NET, C#.NET etc.
SQL stands for Structured Query Language. SQL is an ANSI (American National Standards Institute) standard. It is the most widely used database language. It is used to store, update, delete and retrieve data. SQL Server is a Microsoft product and usually used with ASP.NET application.