If you have a quad, transmitter or any other device that came with a charger (like a DJI product) you should use it for charging that device.
However, in the FPV world you'd typically buy batteries and have to also get a charger.
Charging LiPo's requires that you know what size battery you have, how high you can charge it and discharge it, and at what rate. Not doing so correctly not only shortens the battery's life, but can also be very dangerous as they can explode and/or burst into flames.
This is well understood by experienced pilots, but newcomers may not know how to properly maintain batteries.
I found this chart that someone created (not me) that may be helpful to those just getting started.
However, in the FPV world you'd typically buy batteries and have to also get a charger.
Charging LiPo's requires that you know what size battery you have, how high you can charge it and discharge it, and at what rate. Not doing so correctly not only shortens the battery's life, but can also be very dangerous as they can explode and/or burst into flames.
This is well understood by experienced pilots, but newcomers may not know how to properly maintain batteries.
I found this chart that someone created (not me) that may be helpful to those just getting started.