A fast charger is a device that quickly charges electronic devices, such as smartphones and tablets. It can charge your device faster than a regular charger, saving you time. Full definition
Then my friend told that never to charge a normal phone with fast charger. (gogi.in)
This means you need different fast chargers for different devices. (howtogeek.com)
The need of fast charger has always been around, but smartphone companies took the time to implement such technologies that will allow fast charging on their devices. (phoneradar.com)