One is if you die for any reason within 28 days of a positive test.
The other is the total where covid was a contributing factor in the death. For example If you test positive for COVID but then struggle on for 6 weeks before dying you wouldn't be included in the daily govt figures.
As a slight aside what goes on a death certificate is often contentious - my dad was admitted to hospital with hear failure, because his heart was so weak he couldn't clear the fluid off his lungs and developed pneumonia. It was pneumonia that went on the death cert.