The majority of modern cameras are powered by a removable rechargeable lithium ion (Li-ion) battery. For most cameras, the battery is installed in a slot on the base of the camera, sometimes this may be where the memory card is also inserted.
Most cameras whether they are DSLR, Bridge or compact will come with their own dedicated battery charger. Usually the charge has capacity for one battery and a plug for mains charging. If you have multiple batteries (a second battery at the least is recommended so that you can always have power in your camera) this may not give a quick enough turnaround.
Third party chargers are available that allow multiple battery charging and that connect via USB cable, allowing them to be used by plugging into laptops, power banks and usb adapter in a vehicle.
Some modern cameras can also be charged directly with a power bank or external adapter.
Usually the battery is stored in the bottom of the camera, there will be a latch of some kind, that prevents the battery from being accidentally released. Under the door there may be another catch, release this and the battery should slide out. When replacing the battery check that the battery is the right way around and never force a battery into place, it should slide into the camera without any problems.
