Decaffeination removes much of the caffeine from green coffee before roasting. It aims to retain an enjoyable coffee while changing that component, but the process is not a promise that the finished drink contains no caffeine at all. Specific product information is more useful than an unspecified decaf label.
The source describes direct and indirect approaches, alongside water-based and carbon-dioxide processing. These refer to how caffeine is separated, not to a universal flavor ranking. Methods, handling and the starting coffee can all influence the result.
When buying, look for a named process and a clear origin or blend description, then evaluate the roast and freshness as you would for another coffee. Brew with a measured starting recipe and adjust according to the cup, rather than assuming all decaffeinated beans need identical treatment. Avoid relying on an old summary for current regulatory thresholds or an exact serving-level caffeine figure. A seller's current product details are the appropriate place to resolve those specific questions.
The conversation
A good question can make a better brew.