Hello,

DigitalOcean Spaces provide S3-compatible object storage which lets you store and serve large amounts of data. You can create them in a few seconds and use them immediately with no configuration. Data transfer is automatically secured with HTTPS, and the available storage capacity scales seamlessly.

Spaces are ideal for storing static, unstructured data like audio, video, and images as well as large amounts of text. Because Spaces are an object storage implementation, use cases like databases, applications written in server-side languages, and mission-critical applications will work best with local storage or block storage.

Refer to below link for more information on Spaces
https://www.digitalocean.com/docs/spaces/

Coming to Block Storage Volumes, it acts like a external HDD to your laptop.

Block storage volumes are network-based block devices that provide additional data storage for Droplets. You can move them between Droplets and resize them at any time. Refer to below for Volume features

https://www.digitalocean.com/docs/volumes/#features

For more insights on Volumes, please check https://www.digitalocean.com/docs/volumes/

Please check this article to better understand the differences between Spaces and Volumes https://www.digitalocean.com/community/tutorials/object-storage-vs-block-storage-services

Let us know if this helps!

Cheers,
Lalitha