About SIM card and eSIM card

Good morning, everyone.

I am going to go to au shop near my parents' house tomorrow.

What I  want to do is to cut my mobile bill.

I decided to switch my phone company and go with a cheap SIM card.

but I don't know well about SIM cards. 

What is SIM card?

I searched on the Internet, it said SIM is initialism.

A SIM card is a "Subsciber Identify Module card". (加入者識別用モジュール)

It is a small card that stores a subscriber's personal identifier, billing information and data.

When you change your SIM card, you don't have to move (backup) data, photos, music and videos.

What is the difference between a SIM card and an eSIM card?

According to Andy Betts (a freelance writer and junior editor for Android at MUO),

This page☛ https://www.makeuseof.com/tag/what-is-esim-better-sim-card/

"An eSIM card is a smaller, built-in version of the traditional SIM card. 

The eSIM is fixed onto the phone's (or other device's) motherboard. 

You don't need to insert it, and you can't remove it.

 You don't have to wait for a new SIM to be delivered to your house. "

It seems that eSIM card is more useful than traditional SIM card.

Ummm...

It is difficult for me to handle information technology goods skillfully.