A "Nano SIM" is the smallest physical version of the Subscriber Identity Module (SIM) card. Introduced in October 2012, this minute SIM card measures 12.3 mm by 8.8 mm, making it 40% smaller than the Micro SIM. Despite its compact size, it offers the same features and functions as its larger counterparts. The Nano SIM card holds the user's phone number, text messages, and other data. It is crucial for connecting to mobile networks, allowing the user to make calls, send messages, and access the internet. It is compatible with most modern smartphones and is widely used across the globe.