Steel and ceramic describe different bearing-ball materials. The label alone does not tell you how a complete skateboard bearing will feel or how long it will last. Construction, fit, lubrication, contamination and care all matter.
What DSCO lists
The DSCO Ceramic product page describes zirconia ceramic balls with steel races. The DSCO Titanium product page describes titanium-alloy balls with steel races. Other DSCO listings describe chromium-steel balls. These are the details stated on the current product pages; check those pages for the complete specification and included parts before ordering.
Do not choose by material name alone
A material name is not a measured speed or service-life result. The website does not provide a controlled comparison showing that one DSCO set is faster or lasts longer than another. Instead, compare the listed construction, pack count, shields, spacers, price and included items. Consider how much maintenance you are prepared to do and the conditions you normally ride in.
See DSCO Ceramic, DSCO Titanium and the bearing comparison. If an exact material or component is important, confirm it on the product page before purchase.