The less-than sign is a sign of inequality. For example, less-than 4 would be written as "< 4".
The less-than sign (<) is an original ASCII character (hex 3C, decimal 60).
The less-than sign is used for an approximation of the opening angle bracket (⟨). ASCII does not have angle brackets.
In Coldfusion, operator .lt. means "less than".
In Fortran, operator .LT. means "less than"; later versions allow <.
In Bourne shell, operator -lt means "less than".
Double less-than sign
In the C++ Standard Library, operator <<, when applied on an output stream, acts as insertion operator and performs an output operation on the stream.
Triple less-than sign
In Bash, <<<word is used as a "here string", where word is expanded and supplied to the command on its standard input, similar to a heredoc.
Less-than sign plus equals sign
The less-than sign plus the equals sign (<=) is used for an approximation of the less-than-or-equal-to sign (≤). ASCII does not have less-than-or-equal-to sign.
In Fortran, operator .LE. means "less than or equal to".
Less-than sign is used in the spaceship operator.