What is an eSIM?
The term "eSIM" simply means an embedded SIM card. There are no physical SIM cards involved and no physical swapping over required by you. eSIM needs to be supported by the network or carrier and enabled by them and not all networks support eSIM as yet.

An eSIM is basically a small chip inside your phone and works in a similar way to the NFC chip that's used for payment tech like Apple Pay and Google Pay.

The information on an eSIM is rewritable, meaning you can decide to change your operator with a simple phone call. They're really easy to add to a data plan – connecting devices with eSIMs to a mobile account can be done in minutes. And, as we mentioned, it was

eSIM is backed by the GSMA, the association of mobile networks and that organisation has defined the standard for eSIM worldwide.

Are there any disadvantages to eSIM?
There could be a disadvantage for consumers in terms of choice. If a phone is sold exclusively, it's possible that all handsets could come pre-loaded with a particular network rather than being open to all.

The days of storing numbers on SIM cards are numbered anyway for most people using Android or iOS thanks to cloud backup, but it does involve a change of mindset for those using older or cheaper phones; you'll no longer be able to swap a SIM card to a new phone physically.

What does eSIM mean for devices?
One of the advantages it offers phone makers is that we should get smaller devices because there's no need to accommodate a SIM card or the tray that holds it. There's also no need for networks to manufacture or distribute lots of SIM cards.

eSIMs will also be great for other devices like laptops and tablets, where seamless connectivity will become the norm.

Vodafone says that eSIMs will enable more connected devices simply because eSIMs don't require so much room inside a device, enabling fitness trackers or even glasses to have stand-alone 4G or 5G connectivity in a way they just weren't able to before.