Presidential pardons - I don't understand

[StealthPolarBear]

I realise this is something that all outgoing presidents do, but this is the first time I've heard of it.
How on earth can this be valid, how does this sit with a (presumably overtly) fair and impartial justice system?
Why does anyone think it's a good thing that someone in a position of power can essentially pick his favourite criminals, and let them off? What reasons do presidents usually use in selecting those to pardon?

I have been following with interest only to see if joe exotic got a pardon, which he didn’t! It seems a really alien concept in the uk!

@gingajewel

I have been following with interest only to see if joe exotic got a pardon, which he didn’t! It seems a really alien concept in the uk!

There is such a thing as a Queen’s pardon here and it’s used occasionally. Perhaps Her Maj will do a last minute flurry of them on her deathbed

I'm just glad he hasn't pardoned Ghislane Maxwell. I really thought he would to keep her quiet about what she might know about him. He's keen on young girls, including his own daughter 🤢

I was curious about Julian Assange.

There was one woman on the list who qualified as a nurse whilst in prison, hope she gets a chance to use it.