Is 1 amp enough to charge a phone?

I'm curious, could you elaborate on the query "Is 1 amp enough to charge a phone?" I understand that amps, or amperes, are a unit of electrical current, but how does this relate to charging a phone? Is there a specific current requirement that phones need to be charged effectively? And if so, how does the 1 amp figure compare to the typical charging needs of a smartphone? Does it depend on the phone's battery capacity or the type of charger used? Additionally, are there any potential drawbacks or risks associated with using a charger that provides 1 amp of current?