An eSIM is a SIM card that lives in software instead of plastic. Your phone already has the hardware for it — activating one is just installing a small profile, usually by scanning a QR code from your provider's app or confirmation email.
Why it beats roaming
Your home carrier's roaming rate is almost always a markup on a local provider's rate. An eSIM lets you buy that local (or regional) data directly, often for a fraction of the price, activated before you've even left the gate.
What you actually need
- An unlocked, eSIM-capable phone (most phones from the last 4-5 years qualify)
- Wi-Fi to install the profile before you land
- Your existing physical SIM stays in for calls/texts on your home number, if you want it to