Less-than symbol < is a mathematical operator indicates the inequality between two values or two numbers. less-than is formed of two lines equal in length and joining at an acute angle opening to the right. It is generally placed between two values signaling that the first value is less than the second value.
Many programming languages like C++ use the less-than sign in ColdFusion, Fortran, and Bourne shell.
The doubles less-than sign≪ means an approximation of much-less-than sign. In C++ and c languages it indicates a binary left shift and output stream in C++; in Ruby framework, it is used to append an element to an array.