This is what you can store on a phone with 32GB:

• About 24GB of files
• About 12,000 songs
• About 25,000 normal camera shots

If you find you're running out of space, you can expand your storage using these methods:

• MicroSD card
  See How to get the best performance from your SD card for information on selecting the best card to use.
• Media transfer protocol
  Use this to transfer files from your phone to your desktop computer, and manage your phone using Windows Media Center or other media organizational tools.
  MTP also allows you to view content on your phone and computer at the same time.
• Cloud storage
  Cloud storage is a great option to access files without keeping them in the device memory. Many cloud storage solutions also provide value-adds such as the ability to instantly back up pictures taken from your device's camera.
  HTC One comes with some cloud storage solutions built in, and other third-party cloud solutions are available on the Google Play store.
• OTG Cable or OTG thumb-drive
  USB OTG (On The Go) cables can be used to plug an external hard drive or thumb-drive directly into your device. Some thumb-drives have an OTG micro-USB plug built in, and can be plugged directly into your device without a cable.
  You will need to download a third party file manager (available on the Google Play Store);some popular file manager applications are ES File Explorer, Astro File Manager, and OI File manager.