There are two things to consider with storage; what type, and how much. Macs are available with traditional Serial ATA (SATA) hard drives, speedy solid state drives (SSDs) and Fusion Drives, newer models come with SSDs as standard.
SSD storage delivers significantly improved performance compared to a traditional hard drive - speed you’ll notice when you start up your Mac, launch an app or work within an app like Logic or Ableton. SSDs have been a standard feature in MacBook Pro’s since the Retina models were introduced in 2012.
The Fusion Drive combines speedy SSD storage with a high-capacity hard drive. macOS intelligently manages what goes where, using the SSD storage for files and apps you access frequently and keeping the rest of your digital life on the roomier hard drive. Fusion Drives are available in iMacs and older generation Mac mini's.
How much storage you need is a question you will have to ask yourself. It’s worth considering this prior to purchase as Mac computers are not designed to be upgraded. If you do need more storage with a current Mac, you can consider external storage and cloud storage such as iCloud, Dropbox or Google Drive.