Use the `global` keyword inside a function to declare a global variable
Declare the variable outside all functions at the module level
Example: `x = 10`
Example inside a function: `global x`
In JavaScript, declare a global variable with `var`, `let`, or `const` outside any function or block
In Python, assign the variable outside the function scope
In PHP, use the `global` keyword inside a function to access a global variable
In C, declare the variable outside all functions
In Java, declare the variable as `static` at class level for shared access