The easiest way to add storage to your Android phone or tablet is with a microSD card, even if it doesn’t support one.
Assuming it does, when buying a microSD card for your phone or tablet, you should first check the manufacturer’s specification or reviews of that device to see what type of cards it will accept.
Many budget phones, for example, will accept only 32GB, while higher-end devices typically handle 128GB. You certainly don’t want to pay out for a 128GB card only to find it won’t work in your phone.
You will find manufacturers offer various types of microSD card, with some claiming to be faster or more secure than others are. For simple storage of your files any microSD card will do, but note that fakes can be found online, so be wary of anything too cheap or brands you haven’t come across before.
If your phone or tablet doesn’t natively support microSD, it’s easy to attach one to make use of on an ad-hoc basis using a microSD card reader, which connects to your phone’s Micro-USB port.