For decades, getting a mobile connection meant inserting a tiny piece of plastic, a Subscriber Identity Module or simply a SIM, that was provided by your telcom operator inside your phone. Over the years, SIM cards have gotten progressively smaller, with telecom providers trimming unnecessary plastic housing, which has ultimately led to the mass use of what is known as a Nano SIM. The basic idea, however, remained unchanged till the introduction of eSIM technology, which allows your mobile connection to be embedded directly on your device.
eSIM vs Physical SIM in India: What You Need to Know

