What are software libraries? How are they useful to programmers ?

A software library is a predefined and available to use, suite of data and programming code in the form of pre-written code/functions/scripts/classes etc., that can be used in the development of new software programs and applications.

Software libraries provide pre-written and tested code for a specific set of functions or features that can be included in a software program, saving programmers time and effort. By utilizing existing libraries, programmers can avoid having to write complex code from scratch and can benefit from the experience and knowledge of other developers who have contributed to the library. This results in more efficient coding, faster development, and more reliable software.