What is the meaning of input/output on a charger?

Just wondering what exactly is the meaning for input and output on a charger?

My iPhone charger is:
Input: 100-240v
Output: 5v-1a

My car charger, is:
Input: 10-30VDC
Output: 5v-2a

Another question is that the charging time for both is the same but from my understandings, the iPhone wall charger is 5 watts, and the car charger is 10 watts, so why do they have the same charging time? Isn't the car charger supposed to be faster since the watts is higher?

What do the differences between the input and output mean?

Input on a charger is the voltage which it receives it also specifies the maximum and minimum voltage required to turn the charger on like on the iPhone charger the input is 100-240v AC while on the car charger input is 10-30v DC. The output means the constant voltage and the maximum current provided on the USB port of the adapter.

Your car charger is a 10W one. But when you charge your iphone in the car there are variation in the currents and voltage received by the charger which are dependent upon the way the car is driven, how many pits are present on the road. Also, now a days the charger and the device can have varied currents depending upon their requirements. That is the main reason why both of them take almost the same time to charge your iphone.

Input is the range of voltages it will operate from
Output is the output voltage and the maximum current it can supply.

When the iPhone is charging the current it draws from the charger is determined by circuitry inside the iPhone. Let's say it draws 0.5A. It will draw 0.5A whether it is connected to a 5V 1A adapter or a 5V 10A adapter. As I said above, the current rating of the adapter is the *maximum* current it can supply.

Neither of your devices is an actual charger, they are both 5 volt current sources that your iphone will then use for charging purposes. It is the iphone that determines the charge rate, and that will be the same for any 5 volt source that it uses. In theory the car adapter can deliver more current than the ac adapter, but the actual current draw is determined by the device it is connected to. For example if you use it with a tablet, the draw will be higher than for the iphone.