Classic redistribution

This is a concept that was popularized by Safemoon. The mechanism incentivizes token holders to hold in order to earn dividends from the transactions (buys and sells). Redistribution is based on percentage (in the contract), current token balance and number of holders.

TL; DR: You receive more tokens automatically.

ADA redistribution

Popularized by BABY and GhostFace, a transaction fee is applied to every single buy /sell order, tokens are then swapped in realtime for ADA and added to a POOL (similar to how liquidity pools work). Holders can then go to a website and manually claim the ADA earned at specific time (daily / weekly / etc …). They can then collect the ADA are based on their token holdings % and the current pool size.

TL;DR: You hold, then go to the website and request your ADA