Smart contracts are self-executing contracts with the terms of the agreement between buyer and seller directly written into code. They automatically execute and enforce the terms of the agreement when certain conditions are met, without the need for intermediaries.

DApps, or decentralized applications, are applications that run on a decentralized network of computers rather than a single centralized server. They utilize blockchain technology to enable peer-to-peer interactions without a central authority controlling the data or transactions.

Ethereum 2.0, also known as Eth2 or Serenity, is an upgrade to the Ethereum blockchain aimed at improving scalability, security, and sustainability. It introduces a new consensus mechanism called Proof of Stake (PoS) to replace the current Proof of Work (PoW) system, which should make the network more efficient and environmentally friendly. Additionally, Ethereum 2.0 aims to increase transaction throughput and reduce latency.