The difference is that a full pardon effectively negates the conviction (or prevents conviction if granted to someone not yet convicted). Any rights lost due to the felony conviction such as voting rights, firearm rights, holding some public offices, and such are restored.
A commutation merely reduces the sentence, sometimes to time already served so that the person is immediately released, and sometimes to a lesser sentence but not on that will result in earlier release (e.g., a President could commute a death sentence to life without parole). It does not restore any rights that were lost due to the felony conviction.
Most of Biden's commutations were for non-violent drug possession, with a large fraction of those being for marijuana. Many of these were for cases that nowadays would not even have been prosecuted.
Compare to Trump. Almost 1600 of his were full pardons for January 6 people. Only 14 of them were commutations, which were to time served.
It appears Trump gives pardons to allies, and one straight forward way to become his ally is send him money.
It’s corruption vs. integrity and justice.
Let’s be on the side of integrity and object to pay-to-play and political pardons, regardless of the party of the administration.
There’s nothing left to be done about Clinton’s pardon, but Trump is president now.
Let’s make him pay a political cost for his corruption.
Obama pardoned his close advisor who lied to the FBI
Clinton pardoned Marc Rich - fugitive who's exwife donated lots of money to the clinton Presidential Library or something.
Grant pardoned his own private secretary
Truman pardoned his own yokel local union mobsters from KC
etc
He pardoned several family members. It should be noted that Hunter is the only one who had actually been charged or convicted of a crime.
The others were all preemptive with the stated reason being that Trump was promising to go after the families of basically anyone he saw as an enemy.
Biden had earlier said he would not pardon Hunter, but that was before Trump won. He pardoned Hunter because he didn't think Hunter would be treated the same as the other prisoners in federal prison with Trump in charge. If Harris had won it is very likely Hunter would not have been pardoned and would have went to prison for the maybe 3 years that most experts predict he would have received.
Considering that a decade from now if you tell someone that the origin of the phrase "trumped up charges" comes from a 300+ year old meaning of the verb "trump" related to an Old French word for deceive and a Middle English word for fabricate they will probably will think you are making it up and the "trump" in the phrase means Donald Trump, it is hard to argue that Biden was wrong.