Storage for my Imac.
HI how can I buy more storage for my Imac? Thank you. Alina
iMac 21.5″, macOS 10.13
Storage or RAM? If you mean storage, the easiest and least expensive is to buy high quality external HD's such as
https://eshop.macsales.com/shop/owc-mercury-elite-pro
However, depending on which iMac you want you can pay an independent Apple Authorized Service Provider to add high capacity internal SSDs in your computer.