TL;DR* Here's what the license entails:
1. Anyone can copy, modify and distribute this software.
2. You have to include the license and copyright notice with each and every distribution.
3. You can use this software privately.
4. You can use this software for commercial purposes.
5. If you dare build your business solely from this code, you risk open-sourcing the whole code base.
6. If you modify it, you have to indicate changes made to the code.
7. Any modifications of this code base MUST be distributed with the same license, GPLv3.
8. This software is provided without warranty.
9. The software author or license can not be held liable for any damages inflicted by the software.
More information on about the LICENSE can be found here
The reason why I confused is the below statement was mentioned in this article https://tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)
All code linked with GPL 3.0 source code must be disclosed under a GPL 3.0 compatible license.
@kssvrk We only use the library under GPLv3 license and managing it on our private servers, we only public our front-end application (web or mobile) to end-users, we don't distribute the binary of the component that uses GNU project since this is on the server-side. So based on our answer, we don't have to make our code-base public, right?
Regarding the library, we could fork it and then use our modified library, that forked repo still license under GPLv3 license