Esdt is an initiative aimed to raise awareness and educate the community around DeFi as a whole, and the different tokens launched by Hatom Labs more particularly.
It provides a detailed description of: 

• *Htokens, the receipts tokens you receive when you supply an asset in the Hatom lending protocol.
• *Staked EGLD, the tokens you receive when you stake your EGLD through the Liquid staking module.
• *HatomUSD, the collateral backed stablecoin native to the Elrond Bloclchain.
• *Synthetic tokens, the pegged tokens whose price is designed to remain the same as a designated asset. 

You can find there, a deeper explanation of each of those tokens, examples of their use cases, their respective utility, and the different interactions each token can perform.