How to decide which iPad to get

The only difference is how much stuff you can store on a higher storage capacity device. It’s no different than how big a hard drive you want on your computer. More storage let’s you keep more stuff on the device, instead of moving data on and off as needed. Storage has nothing to do with speed if the device.

Memory is the volatile RAM that iOS itself and apps run in - and there is no options for RAM with any iOS device. Your only option is in how much storage you wish to pay for.

My advice, since iOS device storage cannot be updated, is to always buy as much storage as possible within your budget.

Glad to see you are looking to shop for a new, more modern and up to date iPad.

A lot has happened with iPad in 8-9 years.

GBs ( Gigabytes ) refers to the amount of internal data storage a device can hold.

The larger the number, the more data you can store inside of a device, before you need to offload this data somewhere else.

Apple’s mobile iOS devices always have fixed, non-upgradeable, internal data storage, so purchase the largest device storage size you can afford.

You can compare iPad models here.

https://www.apple.com/ipad/compare/

The iPad compare models with a “Buy” button are Apple's current, new iPad lineup for purchase.

All others are older model iPads no longer, directly, for sale, as new, by Apple.'

Some of these olded models can still be had through Apple's Refurbished & Clearance section of the Apple Website.

Best of Luck to You!