Is this is true

Question

After learning any programming language when you start programming your business will be bound to call libraries and classes

Answer 1

how i can Know classes Which I need

Answer 2

for example if i want create simple data base have to me search in the web and take of the web site and take of other web sit which i need

Answer 3

yes, this is true.The libraries are your tools. Where you can build beautifull programs with. You do not want to invent the wheel. A carpenter does not make his nails or invent them. He just uses them to make beatifull things