The "const" keyword in programming languages like C++ and others signifies a constant, immutable value that cannot be altered after initialization. When applied to a variable, it ensures that the variable's value remains constant throughout its lifetime. Attempting to modify a "const" variable will result in a compilation error.
This keyword ensures data integrity and readability and prevents unintended modifications, making it valuable in scenarios where a variable should not be changed once assigned. Using "const" also aids in code optimization and allows the compiler to make certain performance enhancements.