Afterlife is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Destroy target creature. It can't be regenerated. Its controller creates a 1/1 white Spirit creature token with flying.

How it works : Afterlife

Original English text — Wizards of the Coast / Scryfall

No additional ruling has been published for this card.

Interactions with other cards

These cards' text mentions Afterlife.

Afterlife Insurance

Creatures you control gain afterlife 1 until end of turn. Draw a card. (When a creature with afterlife 1 dies, create a 1/1 white and black Spirit creature token with flying.)

Tithe Taker

During your turn, spells your opponents cast cost {1} more to cast and abilities your opponents activate cost {1} more to activate unless they're mana abilities. Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Indebted Spirit

Bestow {2}{W} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.) Afterlife 1 (When this permanent is put into a graveyard from the battlefield, create a 1/1 white and black Spirit creature token with flying.) Enchanted creature gets +1/+1 and has afterlife 1.

Ministrant of Obligation

Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

Orzhov Enforcer

Deathtouch Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Seraph of the Scales

Flying {W}: This creature gains vigilance until end of turn. {B}: This creature gains deathtouch until end of turn. Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

Imperious Oligarch

Vigilance Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Knight of the Last Breath

{3}, Sacrifice another nontoken creature: Create a 1/1 white and black Spirit creature token with flying. Afterlife 3 (When this creature dies, create three 1/1 white and black Spirit creature tokens with flying.)

Knight of Sorrows

This creature can block an additional creature each combat. Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Syndicate Messenger

Flying Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Orzhov Racketeers

Whenever this creature deals combat damage to a player, that player discards a card. Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)