The symbol for not equal to in Excel is <. It is used to compare two values and returns a TRUE or FALSE result. For example, if you want to check if the value in cell A1 is not equal to the value in cell B1, you can use the formula "=A1<B1". This will return TRUE if the values are not equal and FALSE if they are equal. You can also use this symbol in combination with other operators, such as greater than or less than, to create more complex comparisons. For example,

1. "=A1<B1 AND A1B1" will return TRUE if the value in cell A1 is not equal to the value in cell B1 and is also greater than the value in cell B1.