Sharepoint - Difference between Document Library and Form Library

Document Libraries in SharePoint consist of your main/core documents. For example a word document, excel, PowerPoint, Visio, pdf, csv, notepad etc.

Form libraries consist of XML forms (InfoPath Forms).

The scope of answer will very huge as there are so many different scenario. But major difference is

Document Library is used to maintain the documents and Form Library is used to maintain the Forms (InfoPath Forms)

• Form Library

If you want detail description about in which scenario we should go with Form Library then please go through this

Comparing SharePoint List and Form Library Forms

From here you can get the idea about when to use Form Library.

• Document Library

And for detailed information about scenarios where to use Document Library you can go through

Top 10 Best Practices for Document Libraries

From here you can get the best functionality provided by the Document Library and if your requirement falls under any of the functionality then you can go through the Document Library

Let me know your thoughts.

Document Library:. It is used for storing documents.

Form Library: . It is used for storing InfoPath forms.

Source: http://www.bizsupportonline.net/blog/2014/what-is-sharepoint-form-library.htm