Meaning of the Symbol @@ in SQL Server

Question

What is the meaning of the symbol @@ in SQL Server?

Answer 1

In SQL Server, symbol @@ is prefixed to global variables.

The server maintains all the global variables. We cannot declare them.

Answer 2

Global variable names begin with a @@ prefix. You do not need to declare them, since the server constantly maintains them. They are system-defined functions and you cannot declare them.

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