Libraries are collection of similar objects or it set predefine classes which are related to the different -2 object for specific tasks and all Libraries are frequently used in source code or object code form, data files, scripts, templates, fonts, and physical storage units such as tape cartridges. Here are some common types of Libraries. We can also say that it is pre-compiled routines that a program can use and these routines are sometimes called modules and stored in object format. In c, c++ and every programming language there are many Library Functions which have some own properties. When we compile the source code into the object code then the linker automatically looks in libraries for routines that it does not find elsewhere.