A is how fast it charges. Think of it as charging 1000mAh per hour, 2000mAh per hour, or 3000mAh per hour. Since your battery is a 2000mAh battery charging it at 2A or 3A should be fine. Unless I was in a hurry I would normally charge it at 2A.
People Also Ask
smartphones takes only the power it needs or handles upto. so you wont see any difference between 3A charger and 2A charger if your phone can support upto 5V 2A charging. But if your phone can take 3A of higher, You will find 3A charger faster than 2A charger As it takes more power available to charge the battery.
2A will charge the phone faster because it's higher current. Though with higher current you need thicker cable - it's lower resistance, thus all that current will go through nicely. Higher current = battery heat.
2A will charge the phone faster because it's higher current. Though with higher current you need thicker cable - it's lower resistance, thus all that current will go through nicely. Higher current = battery heat.