The less-than sign is a sign of inequality. The less-than symbol is used in various operations that usually pertain to work being done mathematically or with a programming language. The symbol looks similar to a sideways "V" and is generally used to show inequality between two numbers or expressions. In mathematics, if there are two expressions being compared as an inequality, the less-than symbol usually goes between the two and symbolizes that the first number is less than the second number, for example 2<4 or x<102. The symbol can also be used to the left of a single number to denote the concept of any lesser number, for example "less than 4" would be written as <4. There are other combinations of the less-than symbol and the 'equals' symbol and multiple less-than symbols which are also used mathematically and computationally.
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 doesn't a have a less-than-or-equal-to sign, but Unicode defines it at codepoint U+2264.
In Fortran, operator .LE. means "less than or equal to".
Less-than sign is used in the spaceship operator.
In an inequality, the less-than sign always "points" to the smaller number. Put another way, the "jaws" always go for the larger number.