What is the difference between a standard SIM vs. a micro SIM vs. a nano SIM vs. eSIM

The main difference in SIMs is the physical size of the actual SIM card.

Standard SIM: this type of card is most commonly found in older devices

Micro SIM: this type of card is found in the 4th generation of iPhones, Galaxy S5, etc

Nano SIM: this SIM is smaller and thinner than Standard and Micro

eSIM: this is an 'embedded' SIM card. There is no physical card to insert/remove and must be supported and enabled by the network or carrier

Optimum Mobile provides a Universal SIM so it fits into various types of devices. Don't worry if you break out the card that is too small, you can pop it back into the larger one - it will still work!